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1. Identify the numerator and denominator of the fraction 5/19. 2. What fraction of...

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dangioffre | Student, College Freshman | eNotes Newbie

Posted September 26, 2010 at 12:18 AM via web

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2. What fraction of the first twelve natural numbers are prime numbers?

few more.

 

3. Find two factors of 6 whose sum is 5.

4. Find the greatest common factor of 66 and 68.

4. 

 

5. 

6.Write the fraction numerator 4 divided by denominator 9 as an equivalent fraction with a denominator of 36.

7. 

 

8. 

 

a few question for a pretest. I need to show work. I can use some help with them thanks

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giorgiana1976 | College Teacher | Valedictorian

Posted September 26, 2010 at 1:10 AM (Answer #1)

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The numerator is above the line of the ratio and the denominator is under the line.

So, the numerator is 5 and the denominator is 19.

2. The ratios formed from the first 12 prime numbers could be:

1/3,1/5,1/7,1/11

3/5,3/7,3/11

5/7,5/11

7/11

3. The factors of 6 are the dividers of 6: {1,2,3,6} or{-1,-2,-3,-6}

1*6 = 6*1 = 6

2*3 = 3*2 = 6

The algebraic sum of 2 factors:

6-1 = 5

2+3 = 3+2 = 5

5. Simplify -21/-66

-21 = -3*7

-66 = -3*2*11

We'll re-write the ratio:

 -21/-66 = -3*7/-3*2*11

We'll simplify by -3:

-3*7/-3*2*11 = 7/2*11

-21/-66 = 7/22

6. 4/9 = .../36

We can notice 36 = 4*9

If we notice that the denominator 9 is multiplied by 4, that means that, we have to keep the proprotion and to multiply the numerator by 4, also.

4/9 = 4*4/9*4 = 16/36

8. 1/(3x+9) = 14

We'll cross multiply and we'll get:

14(3x+9) = 1

We'll remove the brackets:

42x + 126 = 1

We'll subtract 126 both sides:

42x = 1-126

42x = -125

We'll divide by 42 and we'll get:

x = -125/42

On the other hand, the equation could be written in this way:

1/3x + 9 = 14

1 + 9*3x = 14*3x

1 + 27x = 42x

We'll subtract 42x both sides:

27x - 42x + 1 = 0

-15x + 1 = 0

-15x = -1

x = -1/-15

x = 1/15

x = 0.06(6)

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neela | High School Teacher | Valedictorian

Posted September 26, 2010 at 12:58 AM (Answer #2)

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. Identify the numerator and denominator of the fraction 5/19.

5 is numerateor

19 is denominator.

2. What fraction of the first twelve natural numbers are prime numbers?

First 12 natural numbers are 1 t,2,3,...12.

The primes within 12 are 2,3,5,7,11 are the  5 primes.

So 5/12 are the fraction of primes within 12  first natural numbers.

few more.

 3. Find two factors of 6 whose sum is 5.

 3*2  = 6 and  3+2 = 5. So 2 factors.

4. Find the greatest common factor of 66 and 68.

66= 2*3*11 and 68 =2*2*17 .

 So 2 is the grearest common factor.

4. The manufacturer of a certain machine claims that the machine will produce 6 parts in 8 hours. At the end of a 40 hour work week in which the machine was in use the entire 40 hours, a supervisor noted that the machine had produced 30 parts. Does this production rate dispute the manufacturer's claim?

 Yes.. The machine @ 6product per 8 hr, should produce (6/8)40 = 30 and it did produce 30 products.

5. Simplify -21/-66

6.Write the fraction  as an equivalent fraction with a denominator of 36.

 4/9 = x/36. So x = 4*36/9 = 16

So 4/9 = 16/36

7. Multiply. Be sure to give the answer in simplest form.

No questions to answer under this number.

 

 

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