Question

5. Resolva as equações do 2º grau.
a)(2x + 1)² - 5(2x + 1) + 4 = 0
b) 3x(x+1) - x = 33-(x-3)²​

Answer 1

$(2x + 1) {}^{2} - 5(2x + 1) + 4 = 0 \\ (2x + 1)((2x + 1) - 5) + 4 = 0 \\ (2x + 1)(2x - 4) + 4= 0 \\ 4 {x}^{2} - 8x + 2x = 0 \\ 4 {x}^{2} - 6x = 0 \\ x(4x - 6) = 0 \\ x = 0 \: e \: x = \frac{3}{2}$

$3x(x + 1) - x = 33 - (x - 3) {}^{2} \\ 3 {x}^{2} + 3x - x = 33 - {x}^{2} + 6x - 9 \\ 4 {x}^{2} - 4x - 24 = 0 \\ x = - 2 \: e \: x = 3$