Question

Thực hiện các phép tính sau:

 \(\frac{5x+10}{4x-8}.\frac{4-2x}{x+2}\);             

 

Answer 1

\(\frac{5x+10}{4x-8}.\frac{4-2x}{x+2}=\frac{\left(5x+10\right).\left(4-2x\right)}{\left(4x-8\right).\left(x+2\right)}\)

                     \(=\frac{5\left(x+2\right).2\left(2-x\right)}{4\left(x-2\right)\left(x+2\right)}\)

                      \(=\frac{5\left(2-x\right)}{2\left(x-2\right)}=-\frac{5}{2}\)

Answer 2

\(\frac{5x+10}{4x-8}.\frac{4-2x}{x+2}=\frac{\left(5x+10\right)\left(4-2x\right)}{\left(4x-8\right)\left(x+2\right)}\\ =\frac{5\left(x+2\right).2\left(2-x\right)}{4\left(x-2\right)\left(x+2\right)}\\ =\frac{5\left(2-x\right)}{2\left(x-2\right)}=-\frac{5}{2}\)