Question

precisooo urgente x(x+1)+x=8

Answer 1

Vamos lá:

$x(x+1)+x = 8 \\\\ x^2+x+x = 8 \\\\ x^2+2x-8 = 0 \\\\ \Delta = b^2-4ac \\\\ \Delta = 2^2-4.1.(-8) \\\\ \Delta = 36 \\\\ x = \frac{-b \pm \sqrt{\Delta}}{2a} \\\\ x' = \frac{-2+ \sqrt{36}}{2.1} \\\\ x' = \frac{-2+6}{2} \\\\ x' = \frac{4}{2} \\\\ \fbox{x' = 2} \\\\ x" = \frac{-2- \sqrt{36}}{2.1} \\\\ x" = \frac{-2-6}{2} \\\\ x" = -\frac{8}{2} \\\\ \fbox{x" = -\quad4}$

Espero ter ajudado.