## Questions and Answers for algebra1

algebra1

### Inverse of a number: find the multiplicative inverse of the number 3 + 2i.

The multiplicative inverse is another name for the reciprocal. Both numbers are such that, if multiplied by the given number, they result in 1. The number 1 is special with regard to the operation...

algebra1

### Find the product of roots of quadratic equation if |x1-x2|=1 and x^2=2x-m.

The roots of the quadratic equation are x1 and x2. |x1 - x2| = 1 and x^2 = 2x - m As x^2 = 2x - m x1^2 = 2* x1 - m x2^2 = 2*x2 - m Subtracting the two we get x1^2 - x2^2 = 2( x1 - x2) => (x1 -...

algebra1

### square root(x+square root(1-x))+square rootx=1. What is x?

We have to solve the equation sqrt (x + sqrt (1 - x)) + sqrt x = 1 sqrt (x + sqrt (1 - x)) + sqrt x = 1 sqrt (x + sqrt (1 - x)) = 1 - sqrt x square both the sides => x + sqrt(1 - x) = 1 + x - 2...

algebra1

### Evaluate the summation (k-1)/k! if k goes from 1 to n.

k! = 1*2*3*...*k (k - 1)/k! = k/k! - 1/k! => 1/(k - 1)! - 1/k! The sum of (k - 1)/k! for k = 1 to n is: 1/0! - 1/1! + 1/1! - 1/2! + 1/2! - 1/3! + ... + 1/(n - 1)! - 1/n! => 1/0! - 1/n!...

algebra1

### What are x and y if 4^(x/y)*4^(y/x)=32 and log 3 (x-y)=1-log 3 (x+y) ?

In this question, I am not clear whether the logs have the base of 3 or 3 is the part of the arguments. I will try to show both cases. Let's consider the given system of equations: 4^(x/y)*4^(y/x)...

algebra1

### If the roots of the equation x^3-9x^2+23x-15=0,are in AP,then one of its roots will be (1)3,(2)9,(3)15(4)0

The roots of x^3 - 9x^2 + 23x - 15 = 0 are in AP. x^3 - 9x^2 + 23x - 15 = 0 => x^3 - 3x^2 - 6x^2 + 18x + 5x - 15 = 0 => x^2(x -3 ) - 6x ( x - 3) + 5(x - 3) =0 => (x^2 - 6x + 5)(x - 3) = 0...

algebra1

### Find the first term and the common difference of the arithmetic sequence if a2-a6+a4=-7 and a8-a7=2a4

The nth term of an arithmetic sequence can be written as a + (n - 1)*d, where a is the first term and d is the common difference. We have a2-a6+a4=-7 => a + d - a - 5d + a + 3d = -7 => a - d...

algebra1

### Write the polar form of the complex number z given by z=6-8i.

The polar form of a complex number z = x + yi is r*(cos A + i* sin A) where tan A= y/x and r = sqrt (x^2 + y^2) Here we have z = 6 - 8i r = sqrt( 6^2 + 8^2) = sqrt (36 + 64) = sqrt 100 = 10 tan A =...

algebra1

### Solve for x log2 x + log4 x + log8 x =11/6

We have to solve for x: log2 x + log4 x + log8 x =11/6 log (a) b = 1/ log (b) a log2 x + log4 x + log8 x =11/6 => 1 / log(x) 2 + 1 / log(x) 4 + 1/log(x) 2 = 11/6 => 1 / log(x) 2 + 1 /...

algebra1

### Solve the system of equations algebraically x^2+y^2=100 x-y=2

We have x^2 + y^2 = 100 and x - y = 2. We have to solve these equations for x and y. x - y = 2 => (x - y)^2 =2^2 => x^2 + y^2 - 2xy = 4 substitute x^2 + y^2 = 100 => 100 - 2xy = 4 =>...

algebra1

### Solve for x and y x^3-y^3=7 x^2+xy+y^2=7

x^3 - y^3 = 7..........(1) x^2 + xy + y^2 = 7 ..............(2) We need to solve the system. First we will rewrite equation (1) as a difference between cubes. ==> x^3 - y^2 = (x-y)(x^2 +...

algebra1

### logarithmsWhat is x if (log2 x)^2+log2 (4x)=4?

We need to solve (log(2) x)^2 + log(2) (4x) = 4 Use the property that log a*b = log a + log b (log(2) x)^2 + log(2) (4x) = 4 => (log(2) x)^2 + log(2) 4 + log(2) x = 4 => (log(2) x)^2 + 2 +...

algebra1

### Determine the imaginary part of complex number z if z^2=3+4i .

We have to determine the imaginary part of the complex number z for z^2 = 3 + 4i Let z = x + yi z^2 = x^2 + y^2*i^2 + 2xyi = 3+ 4i => x^2 - y^2 + 2xyi = 3 + 4i equate the real and imaginary...

algebra1

### How can I use substitution in the problem 2x-y=5, 3x-2y=9 ? How can I use substitution in the problem 2x-y=5, 3x-2y=9 ?

To solve 2x - y = 5 ...(1) 3x - 2y = 9 ...(2) using substitution take (1) 2x - y = 5 => y = 2x - 5 substitute in (2) 3x - 2(2x - 5) = 9 => 3x - 4x + 10 = 9 => -x = -1 => x = 1 y = 2x -...

algebra1

### What is the multiplicative inverse of 6-3i?

The multiplicative inverse of an element of a set is another element of this set such that the product of the two elements is a multiplicative identity. In the given set of complex numbers, the...

algebra1

### Given the roots 6 and 7, determine the quadratic equation?

The roots of a quadratic equation are given as 6 and 7. This means that x - 6 = 0 and x - 7 = 0 We can write ( x - 6)( x - 7) = 0 => x^2 - 6x - 7x + 42 = 0 => x^2 - 13x + 42 = 0 Therefore the...

algebra1

### What is the real solution of the system x^2+y^2=16, xy=3 ?

We have the system of equations x^2 + y^2 = 16 and xy = 13 to solve for x. xy = 3 => x = 3/y...(1) Substitute this in x^2 + y^2 = 16 => (3/y)^2 + y^2 = 16 => 9 + y^4 = 16y^2 => y^4 -...

algebra1

### Find all the zeros of the function f(x)=x^2-8x-9

We have to find the zeros of the function f(x) = x^2 - 8x - 9 For this we equate f(x) to 0 and solve the quadratic equation that is obtained. f(x) = 0 => x^2 - 8x - 9 = 0 => x^2 - 9x + x - 9...

algebra1

### Polynomials . Find the polynomial with lowest degree having the following zeros : 2 and 2i .

A polynomial has complex roots in pairs of conjugates. As the polynomial has roots 2 and 2i, it also has -2i as a root. The polynomial is: (x - 2)(x - 2i)(x + 2i) => (x - 2)(x^2 - 4i^2) => (x...

algebra1

### math problem. log72 (6) + log 72 (8) = a and log6 4=b-1 . Prove that a(b+3)-3b+1=0.

It is given that log(72) 48 = a and log(6) 24 = b a = log(72) 48 = log(6) 48/ log(6) 72 => log(6) (6*8)/log(6) 6*12 => [1 + log(6) 8]/[1 + log(6) 12] => [1 + 3*log(6) 2]/[2 + log(6) 2] b...

algebra1

### Solve the equation. e^2x - 6e^x + 5 = 0

We have to solve: e^2x - 6e^x + 5 = 0 e^2x - 6e^x + 5 = 0 let e^x = t => t^2 - 6t + 5 = 0 => t^2 - 5t - t + 5 = 0 => t(t - 5) - 1( t - 5) = 0 => (t - 1)(t - 5) = 0 => e^x = 1 and e^x...

algebra1

### Determine the complex number z if (3z-2z')/6=-5? z' is the conjugate of z.

We have to find the complex number z given that (3z - 2z')/6 = -5 Let z = a + ib, z' = a - ib (3z - 2z')/6 = -5 =>(3(a + ib) - 2(a - ib)) = -30 => 3a + 3ib - 2a + 2ib = -30 => a + 5ib =...

algebra1

### x^log2 x + 8*x^-log2 x = 6. What is x?

We have to solve for x given that x^log2 x + 8*x^-log2 x = 6 x^log(2) x + 8*x^(- log(2) x) = 6 => x^log(2) x + 8/x^(log(2) x) = 6 Let x^log(2) x = y => y + 8/y = 6 => y^2 - 6x + 8 = 0...

algebra1

### What are the real solutions of the equation log(x+2) x + logx (x+2)=5/2 ?

We have to find the real solutions of log(x+2) x + log(x) (x+2) = 5/2. We use the relation log (a) b = 1/log (b) a and log a + log b = log a*b log(x+2) x + log(x) (x+2) = 5/2 => 1/ log (x) (x+2)...

algebra1

### Solve the simultaneous equations x^2+y^2=10 , x^4+y^4=82

We have to solve the simultaneous equations x^2 + y^2=10 ...(1) x^4 + y^4=82 ...(2) let a = x^2 and b = y^2 This gives a + b = 10 and a^2 + b^2 = 82 a + b = 10 => a^2 + b^2 + 2ab = 100...

algebra1

### I don't know to find parabola mx^2+2mx+x+m-1. all i know is the extreme of parabola is on the line 9x-3y-3.

The extreme of the parabola is determined by finding the first derivative and equating it to 0. We then solve for x. y = mx^2+2mx+x+m-1 y' = 2mx + 2m + 1 = 0 => 2mx = -2m - 1 => x = (-2m - 1)...

algebra1

### Solve the equation in z : 2z+6i = z/2i+5i-7.

We have to solve 2z + 6i = z/2i + 5i - 7 2z + 6i = z/2i + 5i - 7 => 2z - z/ 2i = -i - 7 => (2z*2i - z) / 2i = (-i - 7) => z( 4i - 1)/2i = (-i - 7) => z = (-i - 7) * 2i / ( 4i - 1) =>...

algebra1

### Solve the following simultaneous equations. 2x – 3y = 5 , x – 2y = 4

We have to solve the following set of simultaneous equations: 2x - 3y = 5 ...(1) x - 2y = 4 ...(2) From (2) x - 2y = 4 => x= 4 + 2y Substitute in (1) 2( 4 + 2y) - 3y = 5 => 8 + 4y - 3y = 5...

algebra1

### need to calculate sum of 3 consecutive terms of arithmetic sequence x+4,3x,13x-2

The terms x + 4, 3x and 13x - 2 are consecutive terms of an arithmetic progression. So we know that they have a common difference 13x - 2 - 3x = 3x - x - 4 => 10x - 2 = 2x - 4 => 8x = -2...

algebra1

### System. Solve the system -2x-y=-9 5x-2y=18

We have to solve -2x - y = -9 ...(1) 5x - 2y = 18 ...(2) 2*(1) - (2) => -4x - 2y - 5x + 2y = -18 - 18 => -9x = -36 => x = 4 substitute in (1) -2x - y = -9 => y = -2*4 + 9 => y = 1...

algebra1

### What is the first term of arithmetic sequence if the sum a1+a2+...a13=130? a4,a10,a7 are also consecutive terms of...

Let the first term of the arithmetic sequence be a and the common difference be d. (a + a + 12d)*(13/2) = 130 => 2a + 12d = 20 => a + 6d = 10 => a = 10 - 6d a4, a10 and a7 are consecutive...

algebra1

### Solve for x the equation 5(8e^2x - 3)^3 = 625?

We have to solve: 5(8e^2x - 3)^3 = 625 for x. 5(8e^2x - 3)^3 = 625 divide both sides by 5 => (8e^2x - 3)^3 = 125 take the cube root of both the sides => 8e^2x - 3 = 5 add 3 to both the sides...

algebra1

### Function Determine whether the function f(x)=(2x-5)/(7x+4) has an inverse and , if so , find the inverse.

We see that for each value of x, f(x)=(2x-5)/(7x+4) has only one value and each value of f(x) can be obtained by only one value of x. The function has an inverse. Let y = f(x)=(2x-5)/(7x+4) express...

algebra1

### What kind of equation is z^4-3z^2+2=0 ?

The equation you have given is z^4 - 3z^2 + 2 = 0. Here you can replace z^2 = x to get a quadratic equation in x which can be solved. z^4 - 3z^2 + 2 = 0 => x^2 - 3x + 2 = 0 => x^2 - 2x - x +...

algebra1

### What is (f o g)(36) if f(x)=6^x and g(x)=log6 x ?

We are given that f(x)= 6^x and g(x) = log(6) x We have to find fog(36) fog(36) = f(g(36)) => f(log(6) 36) => 6^(log (6) 36) we know that a^(log(a) x) = x => 36 The required solution for...

algebra1

### Geometric Progression What is the value of x and y if 2, x, y, 16 form a geometric progression ?

Consecutive terms of a GP have a common ratio. if 2, x, y, 16 form a GP. => 16/y = x/2 => x = 32/y y/x = x/2 Substitute x = 32/y => y/(32/y) = (32/y)/2 => 2y = (32/y)^2 => 2y^3 =...

algebra1

### Determine the numbers a,b if the law of composition x*y=xy+2ax+by is commutative.

We have to determine a and b given that for x*y = xy + 2ax + by, the * operator is commutative. x*y = y*x => xy + 2ax + by = yx + 2ay + bx => 2ax + by = 2ay + bx equating the coefficients of...

algebra1

### How to find domain of function f(x)=(x-2)/(x^2-4)? How to find domain of function f(x)=(x-2)/(x^2-4)?

The domain of a function f(x) is all the values x for which f(x) gives real values. f(x)=(x-2)/(x^2-4) => (x - 2)/(x - 2)(x + 2) => 1/(x + 2) This is not defined when x = -2 The domain is R -...

algebra1

### composition of functions Find f(f(4)) if f(x)=14x+13.

It is given that f(x)=14x+13. f(f(4)) given that f(4) = 14*4 + 13 => f( 14*4 + 13) => f(69) => 14*69 + 13 => 979 The value of f(f(4)) = 979

algebra1

### Complex numbers Sum the complex numbers 3+2i+1-5i

The sum of 3+2i+1-5i is found by adding the real terms together and the complex terms, or the terms that contain i, together. 3+2i+1-5i => 3 + 1 + 2i - 5i => 4 - 3i The required result of...

algebra1

### Graphs Prove that the graphs of the functions f(x)=2x+1 and g(x)=x^2+x+1 have a point of intersection

Two graphs have a point of intersection if the equations of the graph have a solution. The equations of the graphs given are: f(x)=2x+1 and g(x)=x^2+x+1 Equating the two we get 2x + 1 = x^2 + x +...

algebra1

### If x and y are 2 real numbers such that 5x+4y=9 and 3x+2y=5, then what is 4x+3y?

We have 5x + 4y = 9 and 3x + 2y = 5. We need to find 4x + 3y. Here we don't need to find x and y. The required result can be obtained by adding 5x + 4y = 9 and 3x + 2y = 5 => 5x + 4y + 3x + 2y =...

algebra1

### Find the argument of the complex number (2+2i)^11/(2-2i)^9

The complex number (2+2i)^11/(2-2i)^9 has to be simplified first. (2+2i)^11/(2-2i)^9 => (4 + 4i^2 + 8i)^5*(2 + 2i) / (4 +4i^2 - 8i)^4 * (2 - 2i) => (8i)^5*(2 + 2i) / (- 8i)^4 * (2 - 2i) =>...

algebra1

### What is the value of x in x+6 = 6square root(x-2)?

We have to solve x+6 = 6* sqrt (x-2) x+6 = 6* sqrt (x-2) square both the sides (x + 6)^2 = 36( x - 2) => x^2 + 12x + 36 = 36x - 72 => x^2 - 24x + 108 = 0 => x^2 - 18x - 6x + 108 = 0 =>...

algebra1

### What is z if z/2 + 3=z'/3 - 2? z complex number

As z is a complex number let it be x + yi. z' = x - yi. If z/2 + 3=z'/3 - 2 => (x + yi)/2 + 3 = (x - yi)/3 - 2 => (x + yi)/2 - (x -yi)/3 = -5 => x/2 - x/3 - i( y/2 - y/3) = -5 => x/2 -...

algebra1

### Simplified product Simplify (8-6i)(-4-4i).

To simplify (8-6i)(-4-4i) open the brackets and multiply the terms (8-6i)(-4-4i) => 8*-4 - 8*4i - 6i*(-4) - 6i*(-4i) => -32 - 32i + 24i + 24i^2 => -32 - 8i - 24 => -56 - 8i The required...

algebra1

### Absolute value equation Absolute value equation : 4*|8x - 8| < 32

We have to solve 4*|8x - 8| < 32 4*|8x - 8| < 32 => |8x - 8| < 8 => |x - 1| < 1 -1 < (x - 1) < 1 -1 < (x - 1) => 0 < x (x - 1) < 1 => x < 2 The values of x...

algebra1

### How to solve the system x+y=3 and x^2/y+y^2/x=9/2?

We have to solve the system x + y = 3 and x^2/y + y^2/x = 9/2 x + y = 3 => x = 3 - y Substitute this in x^2/y + y^2/x = 9/2 => (3 - y)^2 / y + y^2 / (3 - y) = 9/2 => (3 - y)(3 - y)^2 + y*...

algebra1

### Solve the equation: Find all solutions of the equation 2x4-11x3+23x2-19x+5 = 0

The equation to be solved is 2x^4 - 11x^3 + 23x^2 - 19x + 5 = 0 We can see that for x = 1, 2 - 11 + 23 - 19 + 5 = 0 This gives us one solution as 1. 2x^4 - 11x^3 + 23x^2 - 19x + 5 = 0 => 2x^4 -...

algebra1

### If log 6 = m and log 5 = n, write log 7.2 as an expression in m and n.

We can write 7.2 as 6*6/5 log 7.2 = log 6*6 / 5 = log 6^2 / 5 Now log (a^b) = b* log a and log (a/b) = log a - log b log (6^2 / 5) => 2 log 6 - log 5 as log 6 = m and log 5 = n => 2m - n...

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