### Home > ACC7 > Chapter 7 Unit 8 > Lesson CC3: 7.2.1 > Problem7-42

7-42.

Simplify the following expressions.

1. $- \frac { 3 } { 4 } - \frac { 2 } { 5 }$

Find a common denominator.

$-\frac{23}{20}$

1. $\frac { 7 } { 8 } - \frac { 2 } { 3 }$

Find a common denominator.

1. $\frac { 1 } { 3 } - \frac { 5 } { 6 }$

Refer to part (a).

1. $1 \frac { 2 } { 3 } + ( - \frac { 2 } { 5 } )$

Recall that adding a negative number is essentially subtraction.

1. $\frac { 4 } { 7 } - ( - \frac { 3 } { 8 } )$

Remember that when you subtract a negative number you are essentially adding it.

$\frac{53}{56}$

1. $- 4 \frac { 1 } { 2 } + 3 \frac { 1 } { 9 }$

Remember, the solution will have the same sign as the larger number.

$-1\frac{7}{18}$