### Home > A2C > Chapter 2 > Lesson 2.1.1 > Problem2-18

2-18.

Perform each operation in part (a) through (d) below.

1. $\frac { m } { 4 } + \frac { m } { 3 }$

Remember to make a common denominator.

$\frac{3\textit{m}}{12}+\frac{4\textit{m}}{12}$

$\frac{7\textit{m}}{12}$

1. $\frac { x } { 2 } - \frac { x - 1 } { 2 }$

Remember to distribute the negative sign.

$\frac{8\textit{ mmy}}{\textit{xmx}}$

1. $( \frac { 8 m ^ { 2 } } { x } ) \cdot ( \frac { y } { m x } )$

This is equivalent to:
$( \frac { 2 } { 3 } ) \div ( \frac { 5 } { 3 } )$

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

Remember division means multiply by the reciprocal of the divisor.

$\left(\frac{2}{3}\right)\cdot\left(\frac{3}{5}\right)$

$\frac{2}{5}$