Simplify the numerator of the first fraction, then multiply.

$\frac{a^2-a}{7}\cdot\frac{1}{a^2}$

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

$\frac{(1-\frac{a}{x})(1-\frac{b}{x})}{c^2}$

See part (a).

See part (b).