Chọn câu đúng? (5a+5b)^2/(3a+3b)^2=5/3

A. $\frac{{\left(5a+5b\right)}^2}{{\left(3a+3b\right)}^2}=\frac{5}{3}$

B. $\frac{{\left(5a+5b\right)}^2}{{\left(3a+3b\right)}^2}=\frac{25}{9}$

C. $\frac{4x^3+4x^2}{x^2-1}=\frac{4x^2}{x^2+1}$

D. $\frac{b^2+b}{a+ab}=\frac{a}{b}$