91Ó°ÊÓ

In the following exercise, subtract:$\frac{11}{15}-\frac{7}{15}$

In the following exercise, subtract:$\frac{9}{13}-\frac{4}{13}$

In the following exercise, subtract: $\frac{11}{12}-\frac{5}{12}$

In the following exercise, subtract:$\frac{7}{12}-\frac{5}{12}$

In the following exercise, subtract:$\frac{19}{21}-\frac{4}{21}$

In the following exercises, use the divisibility tests to determine whether each number is divisible by $2,3,5,6,and10.$
$942$

In the following exercise, subtract:$\frac{17}{21}-\frac{8}{21}$

In the following exercise, subtract:$\frac{5y}{8}-\frac{7}{8}$

In the following exercise, subtract:$\frac{11z}{13}-\frac{8}{13}$

In the following exercise, subtract:$-\frac{23}{u}-\frac{15}{u}$