Question

\(\left(x-1\right)\left(x+2\right)>\left(x-1\right)^2+3\)

Answer 1

Answer 2

\(bpt\Leftrightarrow x^2+x-2>x^2-2x+1+3\\ \Leftrightarrow3x>6\\ \Leftrightarrow x>2\)

Vậy ....

Answer 3

Ta có: \(\left(x-1\right)\left(x+2\right)>\left(x-1\right)^2+3\)

\(\Leftrightarrow x^2+x-2-x^2+2x-1-3>0\)

\(\Leftrightarrow3x-6>0\)

hay x>2

Vậy: S={x|x>2}