ADD AND SUBTRACT FRACTIONS

Example 1 :

Find the value of :

3/4 + 1/4

Solution :

The fractions above have the same denominator, that is 4.

So, take the denominator once and combine the numerators.

3/4 + 1/4 = (3 + 1)/4

= 4/4

= 1

Example 2 :

Find the value of :

7/15 + 13/15 + 11/15

Solution :

The fractions above have the same denominator, that is 15.

So, take the denominator once and simplify the numerators.

7/15 + 13/15 + 11/15 = (7 + 13 + 11)/15

= 31/15

Example 3 :

Find the value of :

10/21 - 3/21

Solution :

The fractions above have the same denominator, that is 21.

So, take the denominator once and simplify the numerators.

10/21 - 3/21 = (10 - 3)/21

= 7/21

= 1/3

Example 4 :

Find the value of :

5/28 + 3/28 - 1/28

Solution :

The fractions above have the same denominator, that is 28.

So, take the denominator once and simplify the numerators.

5/28 + 3/28 - 1/28 = (5 + 3 - 1)/28

= 7/28

= 1/4

Example 5 : 

Find the value of :

1/12 + 3/18

Solution :

The fractions above have different denominators.

Find the least common multiple of the denominators.

Least common multiple of (12, 18) = 36.

Now, make the denominator of each fraction 36 using multiplication.

1/12 = (1 ⋅ 3)/(12 ⋅ 3) = 3/36

3/18 = (3 ⋅ 2)/(18 ⋅ 2) = 6/36

1/12 + 3/18 :

= 3/36 + 6/36

= (3 + 6)/36

= 9/36

= 1/4

Example 6 : 

Find the value of :

5/16 - 7/20

Solution :

The fractions above have different denominators.

Find the least common multiple of the denominators.

Least common multiple of (16, 20) = 80.

Now, make the denominator of each fraction as 80 using multiplication.

5/16 = (5 ⋅ 5)/(16 ⋅ 5) = 25/80

7/20 = (7 ⋅ 4)/(20 ⋅ 4) = 28/80

5/16 - 7/20 :

= 25/80 - 28/80

= (25 - 28)/80

= -3/80

Kindly mail your feedback to v4formath@gmail.com

We always appreciate your feedback.