Question

Cho mk hỏi:

Tìm x biết:(x-1).(x+2)=(x-2)^2

Thank ạ

Answer 1

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

\(\Rightarrow\left(x-1\right)x+\left(x-1\right)2=\left(x-2\right)\left(x-2\right)\)

\(\Rightarrow x^2-x+2x-2=\left(x-2\right)x-\left(x-2\right)2\)

\(\Rightarrow x^2+x-2=x^2-2x-\left(2x-4\right)\)

\(\Rightarrow x^2+x-2=x^2-2x-2x+4\)

\(\Rightarrow x^2+x-x^2+2x+2x=4+2\)

\(\Rightarrow5x=6\)

\(\Rightarrow x=\frac{6}{5}\)