Question

Resolva a equação -x (-x + 10) = -4 (-x2 - 2)

Answer 1

$-x(-x+10)=-4(-x^{2}-2) \\ x^{2}-10x=4x^{2}+8 \\ 4x^{2}-x^{2}+10x+8=0 \\ 3x^{2}+10x+8=0 \\ \\ delta=100-96=4 \\ \\ x'= \frac{-10+2}{6} = \frac{-8}{6} = \frac{-4}{3} \\ \\ x''= \frac{-10-2}{6}= \frac{-12}{6}=-2 \\ \\ S=[- \frac{4}{3}; -2 ]$