In each of the following, find an equivalent form of the rational number having a common denominator:

$\frac{5}{7},\frac{3}{8},\frac{9}{14}$ and $\frac{20}{21}$

Determine whether the following rational number is in the lowest form or not:

$\frac{65}{84}$

Determine whether the following rational number is in the lowest form or not:

$\frac{-15}{32}$

Determine whether the following rational number is in the lowest form or not:

$\frac{24}{128}$

Determine whether the following rational number is in the lowest form or not:

$\frac{-56}{-32}$

Express the following rational number to the lowest form:

$\frac{4}{22}$

Express the following rational number to the lowest form:

$\frac{-36}{180}$

Express the following rational number to the lowest form:

$\frac{132}{-428}$

Express the following rational number to the lowest form:

$\frac{-32}{-56}$