1,3,5,7 примеры пожалуйста..

Решите задачу:

$1) \frac{a^{2} - ax }{ a^{2}x - ax^{2} } = \frac{a(a-x)}{ax(a-x)} = x \\ 3) \frac{ 4p^{2} - 16p^{3} }{ 12p^{2} - 3p} = \frac{ 4p^{2}(1-4p)}{3p(4p-1)} = \frac{4p(1-4p)}{3(4p-1)} \\ 5) \frac{ b^{3} + 1}{ b^{2} - b + 1} = \frac{(b+1)( b^{2} -b + 1)}{ b^{2} - b + 1} = b + 1 \\ 7) \frac{ x^{2} - 8x + 16}{ax-4a} = \frac{(x - 4)^{2}}{a(x - 4)} = \frac{x - 4}{a}$