Question

Qual é a resposta dessa conta 
(x+1)(x-3)=-3?

Answer 1

$(x+1)(x-3)=-3\\x^2-3x+x-3=-3\\x^2-2x=0\\x(x-2)=0\\\\\boxed{x'=0}\\\\x''-2=0\\\\\boxed{x''=2}$

Answer 2

$(x+1)(x-3)=-3 \\ \\ x^{2} -2x -3 = - 3 \\ \\ x^{2} -2x - 3 + 3 = 0 \\ \\ x^2 - 2x = 0$

$x^2 - 2x = 0 \\ \\ \\ x (x - 2) = 0 \\ \\ \\ x' = 0 \\ \\ \\ x - 2 = 0 \\ \\ x'' = 2$

S = {0, 2}