Question

Quanto é 4x(X+1)=12 ?

Answer 1

Vamos lá :

$4x(x+1)=12 \\ \\ 4x^2 + 4x - 12 = 0 ~~: ~~4 \\ \\ x^2 + x - 3 = 0 \\ \\ a = 1 ~~;~~b = 1 ~~;~~c = - 3 \\ \\ \Delta = b^2-4ac \\ \Delta = 1^2 - 4.1.(-3) \\ \Delta = 1 + 12 \\ \Delta = 13 \\ \\ x = \frac{-b~\pm \sqrt{\Delta} }{2a} \\ \\ x = \frac{-1 ~\pm \sqrt{13} }{2.1} \\ \\ x = \frac{-1 ~\pm \sqrt{13} }{2} \\ \\ \\ x' = \frac{-1~+~ \sqrt{13} }{2} ~~~~~x'' = \frac{-1~-~ \sqrt{13} }{2}$

Espero ter ajudado !!!