### Home > ACC6 > Chapter 7 Unit 7 > Lesson CC1: 7.1.3 > Problem7-34

7-34.

Compute each sum or difference.

Before adding or subtracting, change one or both fractions so that they have the same denominator.

Use a Giant One to convert to an equivalent fraction.

1. $\frac { 11 } { 12 } - \frac { 2 } { 3 }$

Find the lowest common denominator.

$(3)(4)=12$

Convert the fraction(s).

$\left ( \frac{2}{3} \right )\left ( \frac{4}{4} \right )=\frac{8}{12}$

Find the sum or difference.

$\frac{11}{12}-\frac{8}{12}=\frac{3}{12}$

Simplify, if necessary.

$\frac{3}{12}=\frac{1}{4}$

1. $\frac { 3 } { 8 } + \frac { 7 } { 12 }$

$\frac{23}{24}$

1. $\frac { 9 } { 10 } + \frac { 5 } { 8 }$

The lowest common denominator is $40$.