......................?
mik ko biết
mong bn thông cảm !$$%
\(\left(x+2\right)^2+\left(x-3\right)^2-2\left(x-1\right)\left(x+1\right)=9\)
<=> \(x^2+2x+4+x^2-6x+9-2\left(x^2-1\right)=9\)
<=> \(2x^2-4x+13-2x^2+2=9\)
<=> \(-4x+15-9=0\)
<=> \(-4x+6=0\)
<=> \(4x=6\)
<=> \(x=\frac{3}{2}\)