3x-2y=8 x=2y-4 solve for x and y
11 Answers
3x-2y=8...(1)
x=2y-4
Subtract 2y
==> x-2y=-4.....(1)
Subtract (1) from (2)
==> 2x=12 ==> x=6
To calculate y, we will use either equation (1) or (2)
x-2y=-4
Substitute with x=6
==> 6-2y=-4
Subtract 6 from both sides:
==> -2y=-10
Divide by -2:
==> y=5
pohnpei397 | College Teacher | (Level 3) Distinguished Educator
The answer here is that x = 6 and y = 5. Here is how you can find this:
The thing to do here is to take the value that you have been given for x in the second equation and substitute it into the first equation. So then you have
3 (2y - 4) - 2y = 8
6y - 12 - 2y = 8
4y = 20
y = 5
Now you take this value of y and substitute it back in to the second equation to find x.
x = 2 (5) - 4
x = 10 - 4
x = 6
krishna-agrawala | College Teacher | (Level 3) Valedictorian
The given simultaneous equations are:
3x - 2y = 8 ... (1)
and
x = 2y - 4
The above equation can be expressed as:
x - 2y = - 4 ... (2)
Subtracting equation (2) from equation (1) we get:
3x - x - 2y + 2y = 8 + 4
2x = 12
Therefore:
x = 12/2 = 6
Substituting this value of x in equation (1):
3*6 - 2y = 8
18 - 2y = 8
-2y = 8 - 18 = -10
Therefore:
y = -10/(-2) = 5
Answer:
x = 6, y = 5
tonys538 | Student, Undergraduate | (Level 1) Valedictorian
The set of equations 3x-2y=8 and x=2y-4 has to be solved for the variables x an y. It is possible for us to determine a unique solution as the number of variables is equal to the number of equations.
From x = 2y - 4, substitute for x in 3x - 2y = 8
3*(2y - 4) - 2y = 8
6y - 12 - 2y = 8
4y = 20
y = 5
x = 2y - 4 = 10 - 4 = 6
The solution of the given set of equations is x = 6 and y = 5
nisarg | Student, Grade 11 | (Level 1) Valedictorian
3x-2y=8
x=2y-4
3x=2y+8
x=2y-4
2x=12
x=6
x=2y-4
6=2y-4
10=2y
5=y
jess1999 | Student, Grade 9 | (Level 1) Valedictorian
3x -2y = 8
x = 2y - 4
First, In the second equation subtract 2y on both sides of the equation
By subtracting, you should get
3x - 2y = 8
x - 2y = -4 now subtract -2y with -2y ( which means subtract 3x with " x " and and 8 with -4 )
By subtracting, you should get
2x = 12 now divide both sides by 2
By dividing, you should get
x = 6 which is your answer for " x "
now plug 6 into one of the equation
6 = 2y - 4 now add 4 on both sides
By adding, you should get
10 = 2y now divide both sides by 2
By dividing you should get
y = 5 which is your answer for " y "
So your answer is x = 6. Y = 5
Wiggin42 | Student, Undergraduate | (Level 2) Valedictorian
(a) 3x-2y=8
(b) x=2y-4
Rearrange b: -x + 2y = 4
Add a and the rearranged b, solve for x:
-x + 2y = 4
+
3x - 2y = 8
-------------------
2x = 12 ----> x = 6
Plug in this value of x into one of the equations (a) or (b) and solve for y.
2y - x = 4
2y = 4 + x
y = (4 + x)/2
y = ( 4 + 6 ) / 2 = 5
Yojana_Thapa | Student, Grade 10 | (Level 1) Valedictorian
3x-2y=8 x=2y-4 Solve for x and y
3(2y-4) -2y = 8
6y - 12 - 2y = 8 (now you combine the like terms)
6y (-12 +12) -2y = (8+12)
6y - 2y = 20
4y = 20 (divide both sides by 4)
y = 5
- now since you have the y value, just plug it in
x = 2(5) - 4
x = 6
- Now plug it in to check
3x-2y=8
3(6) - 2(5) = 8
18 - 10 = 8
8 = 8
Jyotsana | Student, Grade 10 | (Level 1) Valedictorian
3x-2y=8
x=2y-4
3(2y-4)-2y=8
6y-12-2y=8
6y-12-2y+12=8+12
6y-2y=20
4y=20
4y/4=20/4
y=5
2(5)-4=x
x=6
So x=6 and y=5
lit24 | College Teacher | (Level 3) Valedictorian
The value for x is given as x=2y-4
So by substituting the value for x in the equation 3x-2y=8 it can be expressed as
3 x (2y-4) -2y = 8
6y-12-2y = 8
4y = 12+8
4y = 20
y=5
Now, substitute the value of y in the equation 3x-2y=8
3x-2 x 5 =8
3x-10=8
3x =10 + 8
3x=18
x=6
Answer: X=6 and y=5
neela | High School Teacher | (Level 3) Valedictorian
To solve:
3x-2y=8..............(1)
x= 2y-4...............(2)
Solution:
We use the method of substitution , as in the second equation there is x given as subject:
x=2y-4 could be substituted in the first equation, So, the 1st equation is rewritten as below:
3(2y-4)-2y =8. This is an equation in one variable y. We collect y on one side and numbers on the other side.
6y-12 -2y=8
4y = 8+12 = 20. Or y = 20/4 = 5 .
x = 2(5)-4 = 6.
So x= 6 and y = 7.