Question

resolva as seguintes equações do 2° grau​

Answer 1

$a) \\ y = - x {}^{2} - x + 12 \\ 0 = - x {}^{2} - x + 12 \\ - x {}^{2} - x + 12 = 0 \\ x {}^{2} + x - 12 = 0 \\ x {}^{2} + 4x - 3x - 12 = 0 \\ x \: . \: (x + 4) - 3(x + 4) = 0 \\ (x + 4) \: . \: (x - 3) = 0 \\ x + 4 = 0 \\ \boxed{\boxed{\boxed{x = - 4}}} \\ x - 3 = 0 \\ \boxed{\boxed{\boxed{x = 3}}}$

$b) \\ y =2 x{}^{2} - 8x + 6 \\ 0 = 2x {}^{2} - 8x + 6 \\ 2x {}^{2} - 8x + 6 = 0 \\ x {}^{2} - 4x + 3 = 0 \\ x {}^{2} - x - 3x + 3 = 0 \\ x \: . \: (x -1) - 3(x - 1) = 0 \\ (x - 1) \: . \: (x - 3) = 0 \\ x - 1 = 0 \\ \boxed{\boxed{\boxed{x = 1}}} \\ x - 3 = 0 \\ \boxed{\boxed{\boxed{x = 3}}}$

att. yrz