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

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

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

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

D. $\frac{{\text{b}}^{\text{2}}+\text{b}}{\text{a}+\text{ab}}=\frac{\text{a}}{\text{b}}$