Question

Answer 1

\(\dfrac{a}{b}=\dfrac{5}{6}\Rightarrow a=\dfrac{5b}{6}\)

\(A=\dfrac{3a-2b}{2a-3b}=\dfrac{3.\dfrac{5b}{6}-2b}{2.\dfrac{5b}{6}-3b}=\dfrac{\dfrac{5}{2}b-\dfrac{4}{2}b}{\dfrac{5}{3}b-\dfrac{9}{3}b}=\dfrac{\dfrac{1}{2}b}{-\dfrac{4}{3}b}=-\dfrac{3}{8}\)

Answer 2

Đặt \(\dfrac{a}{5}=\dfrac{b}{6}=k\)

\(A=\dfrac{3a-2b}{2a-3b}=\dfrac{15k-12k}{10k-18k}=\dfrac{-3}{8}\)