\(\left(a+b\right)\left(2b-a-4\right)=\left(a-2b\right)\left(5-a-b\right)\)=> \(\frac{2b-a-4}{a-2b}=\frac{5-a-b}{a+b}\)=> \(\frac{-\left(a-2b\right)-4}{a-2b}=\frac{5-\left(a+b\right)}{a+b}\)=. \(-1-\frac{4}{a-2b}=\frac{5}{a+b}-1\)=> \(\frac{-4}{a-2b}=\frac{5}{a+b}\)=> \(-4\left(a+b\right)=5\left(a-2b\right)\)=> \(-4a-4b=5a-10b\)=>6b=9a=>\(a=\frac{2}{3}b\)thay vào biểu thức là...
Đọc tiếp
\(\left(a+b\right)\left(2b-a-4\right)=\left(a-2b\right)\left(5-a-b\right)\)
=> \(\frac{2b-a-4}{a-2b}=\frac{5-a-b}{a+b}\)
=> \(\frac{-\left(a-2b\right)-4}{a-2b}=\frac{5-\left(a+b\right)}{a+b}\)
=. \(-1-\frac{4}{a-2b}=\frac{5}{a+b}-1\)
=> \(\frac{-4}{a-2b}=\frac{5}{a+b}\)=> \(-4\left(a+b\right)=5\left(a-2b\right)\)=> \(-4a-4b=5a-10b\)=>6b=9a=>\(a=\frac{2}{3}b\)
thay vào biểu thức là ra
