# How do you simplify 3x (x -1) - 4 (x^2 - x)?

$\implies - {x}^{2} + x$
$\implies 3 x \left(x - 1\right) - 4 \left({x}^{2} - x\right)$
$\implies 3 {x}^{2} - 3 x - 4 {x}^{2} + 4 x$
$\implies - {x}^{2} + x$