Question

Resolve a equacao do segundo grau:
$(x-3)^{2}$ + 3 = 3 (7-2x)

Answer 1

(x - 3)² + 3 = 3 . (7 - 2x)

=> x² - 6x + 9 + 3 = 21 - 6x

=> x² - 6x + 12 - 21 + 6x = 0

=> x² - 9 = 0

=> x² = 9

=> x = √9

=> x' = 3 e x" = - 3

S = {-3,3}

Answer 2

$(x-3)^{2} + 3 = 3 (7-2x) \\ \\ (x-3)(x-3)+3=21 - 6x \\ \\ x^2-3x-3x+9+3=21-6x \\ \\ x^2-6x+12=21-6x \\ \\ x^2 -6x+6x=21-12 \\ \\ x^2=9 \\ \\ x = \sqrt{9} \\ \\ x' = 3 \\ \\ x" = - 3$