Question

B= (-5x+4)(3x-2)+(-2x-2) tại x =-2

Answer 1

\(B=\left[\left(-5\right).\left(-2\right)+4\right]\left[\left(-2\right).3-2\right]+\left[\left(-2\right).\left(-2\right)-2\right]=\left(10+4\right).\left[\left(-6\right)-2\right]+2=14.\left(-8\right)+2=-112+2=-110\)

Answer 2

\(B=\left(-5x+4\right)\left(3x-2\right)+\left(-2x-2\right)\)

\(=-15x^2+10x+12x-8-2x-2\)

\(=-15x^2+20x-10\)

\(=-15\times\left(-2\right)^2+20\times\left(-2\right)-10(x=-2)\)

\(=-60-40-10\)\(=-110\)

vậy \(B=-110\)