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Question

I need help with these math questions... can some one give me a hand and show me how to do it... .


1.) Which of the following pairs of numbers contain like fractions?
a. 6/7 & 1 5/7 c. 5/6 & 10/12
b. 3/2 & 2/3 d. 3 1/2 & 4 3/4

2.) 7 1/5 - 6 2/5?
a. 13 3/5 c. 4/5
b. 1 4/5 d. 1 1/5

3.) What is the sum of 2/5 & 2/4
a. 8/20 c. 10/20
b. 9/10 d. 6/7

4.) What is the least common denominator of 3/4, 4/5 & 2/3?
a. 20 c. 12
b. 15 d. 60

5.) What is the product of 3 2/3 & 14 2/5?
a. 52 4/15 c. 52 4/5
b. 54 d. 42 4/5

Answer 1

Okay, look at #1.
The ones that are alike have the same denominator.

#2. 7 1/5 - 6 2/5
This is just regular subtraction. It just looks different because of the fractions. I'd start by subtracting the 6 from the 7 1/5, which leaves 1 1/5 - 2/5. We know 1 is 5/5, so 1 1/5 = 6/5.

so we have 6/5 - 2/5 = 4/5

3. 2/5 + 2/4 This one will need to have both fractions converted to ones with the same denominator. Since 20 is the least common denominator (5 times 4) we'll use that. To get there, we need to multiply (2/5)(4/4) and (2/4)(5/5). Notice that by doing this, we're keeping everything equal because we're multiplying both by 1.

so we get 8/20 + 10/20 = 18/20 which must be reduced by dividing the numerator and denominator by 2. and that gives us 9/10.

4. Okay, the least common denominator of these fractions is one that all three denominators will divide into without remainders. When we figure these, we need to look at multiples of each one, to see if the others will divide into it. In this case, we'll have to multiply 4 x 5 x 3 to get 60. Don't fall into the trap of always multiplying them to get the least common denominator, though. Sometimes the least one will be much less than what you'd have by multiplying all of them.

5. A product is what you get when you multiply. So what I'd do is convert both of these numbers to fractions and then multiply them and reduce the result. So... 3 2/3 = 11/3 and 14 2/5 = 72/5
that gives us 11/3 x 72/5, then multiply numerators and denominators to get (11 x 72) / (3 x 5) = 792/15 which reduces to 52 12/15 = 52 4/5

There ya go.

Answer 2

1) c.
5/6 =10/12

10/2=5
12/2=6

so they are like fractions

2) c.
4/5

first you must change the fractions into improper fractions
7 1/5=
Multiply the whole number 7 by the denominator 5 then add the numerator 1. That will give you 36. Put that over the denominator 5.
so that is 36/5

6 2/5=
Multiply the whole number 6 by the denominator 5 then add the numerator 3. That will give you 32. Put that over the denominator 5.
so that is 32/5

Then do it as a normal subtraction problem
36 - 32 = 4 so that is 4/5

3) b.
9/10

First you have to get a common denominator I chose 20.
2/5 + 2/4
Multiply 2/5 4 on top and 4 on bottom which will give you 8/20
Multiply 2/4 5 on top and 5 on bottom which will give you 10/20

So you have 8/20 + 10/20 = 18/20 = 18/2 = 9
20/2 =10

So that is 9/10

4)d.
60

Multiply all of the denominators 4x5x3 = 60

5) c

52 4/5

Make improper fractions 3 2/3 = 3x3+2= 11 so that is 11/3
14 2/5= 14x5+2=72 so that is 72/5

11x72=792 792/15
3x5 = 15

792/15 = 52.8= 52 4/5

Answer 3

Okay, here's how to do it. This is long, but it's really going to help.

1)What this question means is which two fractions are alike (or are equal to each other). To find this, look at the fractions.
a. 6/ 7 and 5/ 7 is not the right answer. They have the same denominator (lower number) but not the same numerator (upper number). Fractions are like unsolved divisions. 6/7 is equal to 6 divided by 7. You know that 6 divided by 7 and 5 divided by seven aren't equal, so this is wrong.

b. the same numbers appear (2/3 & 3/2), but that doesn't mean they are the same. 2/3 is equal to 0.666..., and 3/2 is equal to 1.5.

c. This is the right answer. To find it, simplify 10/12. You do this by dividing both the top and the bottom by the same number. e.g.
1/2 = (1x3) / (2x3) = 3/6
so 1/2 = 2/4, 3/6, 4/8, etc.
simplify 10/12 by dividing by 2, you get 5/6, the same #

2) To find this do the equation yourself in separate sections.
First, the whole numbers. 7-6= 1. You have 1 left over.
Then, 1/5 - 2/5. This is not possible so you take the 1 left over and add it to the 1/5, so the equation is:
1 1/5 - 2/5 = 4/5 (in fractions, you take away the numerators)
Remember= you can only add & subtract two fractions if the denominator is the same in both.

3) You can't find it at first, so you have to multiply both equations
to have equal denominators. You want the denominator 20, because it is the smallest denominator that both 5 and 4 can be multiplied to.
STEP 1= 2/5 x4 = (2x4) / (5x4) = 8/20
STEP 2= 2/4 x 5 = (2x5) / (4x5) = 10 / 20
STEP 3= add them together.
8/20 + 10/ 20 = 18 / 20

4) Fist, you need to know what the least common denominator is. You know that denominator is the number on the bottom. When you have two fractions with different denominators, you want to multiply the equations to find one equal denominator, like we did in Q3.
The Least Common Denominator, or LCD, is the smallest number that all denominators shown can be multiplied to ( or, in other words, are a factor of). First off, it has to be divisible by 5. so it ends with a 5 or a 0, second, it has to be divisible by 4, so it has to be an even number, so it HAS to end with 0. Now find the multiples of 3 that end with 0, easy.

30, 60, 90, etc.
30 would be the smallest but it cannot be divided by 4. 60 is divisible by 4, so that is the solution.

5) To do this, find the LCD of both fractions, which is 15=
STEP 1= add the whole digits together.
3 + 14 = 17

STEP 2= 2/3 x5 = (2x5) / (3x5) = 10/15
STEP 3= 2/5 x3 = (2x3) / (5x3) = 6 / 15
STEP 4= add them together.
10/15 + 6/15= 16/15

STEP 5= 17 + 16/15= 17 16/ 15
STEP 6= Notice that the numerator is bigger than the denominator. You have to transform the number (a.k.a: take away the whole #)
17 16/15 = 18 1/15
Your answer is 18 1/15

Good Luck

Answer 4

1. C 10/12 can be reduced to 5/6 (by dividing both numerator and denominator by 2)
2. 7 1/5 can also be written as 36/5 and 6 2/5 can be written as 32/5. 36/5 - 32/5 = 4/5 so the answer is C
3. Get a common denominator by multiplying the first by 4 and the second by 5. 8/20 + 10/20 = 18/20 which can be reduced to 9/10 so the answer is B
4. The least common denominator is the smalled number that each would be divisible into (multiply all three denominators 4 X 5 X 3 = 60) so answer is D

I can't remember how to do #5

Answer 5

1) a 2) c 3) b 4) d 5) c

Answer 6

1. C
2. 4/5
3. 9/10
4. 60
5. 52 4/5

Answer 7

1.c
2.b
3.b
4.d
5.a