e) $\frac{2x+2y+5x+5y}{2x+2y-5x-5y}$ = $\frac{2(x+y)+5(x+y)}{2(x+y)-5(x+y)}$ = $\frac{7(x+y)}{-3(x+y)}$ = $\frac{-7}{3}$
g) $\frac{2ax^{2}-4ax+2}{5b-5bx^{2}}$ = $\frac{2a(x^{2}-2x+1)}{-5b(x^{2}-1)}$ = $\frac{2a(x-1)^{2}}{-5b(x-1)(x+1)}$ = $\frac{2a(x-1)}{-5b(x+1)}$
h) $\frac{4x^{2}-4xy}{5x^{3}-5x^{2}y}$ = $\frac{4x(x-y)}{5x^{2}(x-y)}$ = $\frac{4x}{5x^{2}}$
f) $\frac{x^{2}-xy}{3xy-3y^{2}}$ = $\frac{x(x-y)}{3y(x-y)}$ = $\frac{x}{3y}$
i) $\frac{(x+y)^{2}-z^{2}}{x+y+z}$ = $\frac{(x+y+z)(x+y-z)}{x+y+z}$ = x+y-z
k) $\frac{x^{6}+2x^{3}y^{3}+y^{6}}{x^{7}-xy^{6}}$ = $\frac{(x^{3})^{2}+2x^{3}y^{3}+(y^{3})^{2}}{x(x^{6}-y^{6})}$ = $\frac{(x^{3}+y^{3})^{2}}{x(x^{3}-y^{3})(x^{3}+y^{3})}$ = $\frac{x^{3}+y^{3}}{x(x^{3}-y^{3})}$
