Adding and subtracting Fractions?

Question

5/13 + 2/5
5/6 - 4/15
13/14 - 1/2
7/8 - 1/2
1/4 + 3/10
1/5 - 1/13

Answer 1

You have to find common denominators before you can add or subtract the two fractions... like this...

PROBLEM 1:

5/13 + 2/5 = 25/65 + 26/65 = 51/65

PROBLEM 2:

5/6 - 4/15 = 25/30 - 8/30 = 17/30

PROBLEM 3:

13/14 - 1/2 = 13/14 - 7/14 = 6/14 = 3/7

PROBLEM 4:

7/8 - 1/2 = 7/8 - 4/8 = 3/8

PROBLEM 5:

1/4 + 3/10 = 5/20 + 6/20 = 11/20

PROBLEM 6:

1/5 - 1/13 = 13/65 - 5/65 = 8/65

Answer 2

get the common deniminator

5/13 + 2/5 = 25/65 + 26/65 = 51/65

5/6 - 4/15 = 25/30 - 8/30 = 17/30

13/14 - 1/2 = 13/14 - 7/14 = 6/14 = 3/7

7/8 - 1/2 = 7/8 - 4/8 = 3/8

1/4 + 3/10 = 5/20 + 6/20 = 11/20

1/5 - 1/13 = 13/65 - 5/65 = 8/65

Answer 3

Find the lowest common denominator, if one of the denominators is a prime number then multiply them.
with 5/13 and 2/5 it is 65 - 13 X 5

5/13 = 25/65
2/5 = 26/65

add the numerators

thus 5/13 + 2/5 = 25/65 + 26/65 = 51/65

in the same way
5/6 + 4/15 = 25/30 + 8/30 = 33/30 = 1and 3/30 = 1 1/10

Answer 4

5/13 + 2/5 = 25/65 +26/65 = 51/65
5/6 - 4/15 = 25/30 -8/30 = 17/30
13/14 - 1/2 = 13/14 - 7/14 = 6/14 = 3/7
7/8 - 1/2 = 7/8 -4/8 = 3/8
1/4 + 3/10 = 5/20+6/20 = 11/20
1/5 - 1/13 = 13/65 - 5/65 = 8/65

Answer 5

5/13 + 2/5 = 25/65 + 26/65 = 51/65

5/6 - 4/15 = 25/30 - 8/30 = 17/30

13/14 - 1/2 = 13/14 - 7/14 = 6/14 = 3/7

7/8 + 3/10 = 70/80 + 24/80 = 94/80 = 47/40

1/4 + 3/10 = 5/20 + 6/20 = 11/20

1/5 - 1/13 = 13/65 - 5/65 = 8/65

Answer 6

I won't answer the whole lot (and nor should anyone else), because you need to know the method.

Generally, make the fractions the same type as each other. That is, change each fraction so they have the same denominator (bottom number). Then you can just add/subtract the top numbers (numerators).

The easiest way is to multiply the top and bottom of each fraction by the bottom of the other.

So for example,
5/13 + 2/5
Multiply top and bottom of 5/13 by 5, to get 25/65
Multiply top and bottom of 2/5 by 13, to get 26/65

Now they are both 65ths, we can just add them up directly.
So 5/13 + 2/5 = 25/65 + 26/65 = 51/65

51 and 65 have no common factors, so 51/65 is the most reduced form of the answer.

You now have the method for doing the rest. Good luck, I genuinely hope this helps.

Answer 7

5/13+2/5=15/65+26/65=41/65
5/6 - 4/15= 65/90-24/90=41/90
13/14 - 1/2=13/14-7/14=6/14=3/7
7/8 - 1/2=7/8-4/8=3/8
1/4 + 3/10= 5/20+6/20=11/20
1/5 - 1/13=13/65-5/65=8/65

Answer 8

LCD 65: 25/65 + 26/65 = 51/65

LCD 30: 25/30 -8/30 = 17/30

LCD 14: 13/14 - 7/14 = 6/14 = 3/7

LCD 8: 7/8 - 4/8 = 3/8

LCD 20: 5/20 + 6/20 = 11/20

LCD 65 again: 13/65 - 5/65 = 8/65

Answer 9

5/6 - 4/15=17/30
13/14 - 1/2 = 3/7
7/8 - 1/2 = 3/8
1/4 + 3/10 = 55/100 or .55 or 11/20

sorry but i'm not good with a denominator of 13

Answer 10

make the denominator the same.

for example 2/3 + 1/6

4/6 + 1/6