Question

(x-1)²=9(x+1)²

Answer 1

=>(3x+3)^2=(x-1)^2

=>3x+3=x-1 hoặc 3x+3=1-x

=>2x=-4 hoặc 4x=-2

=>x=-1/2 hoặc x=-2

Answer 2

\(\left(x-1\right)^2=9\left(x+1\right)^2\)

\(\Rightarrow\left(x-1\right)^2=\left[3.\left(x+1\right)\right]^2\)

\(\Rightarrow x-1=3x+3\)

\(\Rightarrow x-3x=3+1\)

\(\Rightarrow-2x=4\)

\(\Rightarrow x=-2\)