Question

rút gọn biểu thức (x² -1) /(x+1)

Answer 1

dùm hằng đẳng thức nhanh hơn nguyen thieu cong thanh

Answer 2

\(\frac{x^2-1}{x+1}=\frac{x^2+x-x-1}{x+1}=\frac{x^2+x-\left(x+1\right)}{x+1}=\frac{x\left(x+1\right)-\left(x+1\right)}{x+1}\)

\(=\frac{\left(x-1\right)\left(x+1\right)}{x+1}=x-1\)

vậy \(\frac{x^2-1}{x+1}=x-1\)