Question

quanto e (x+3)^2=2x(x+7)

Answer 1

(x + 3)² = 2x . (x + 7)(x + 3) . (x + 3) = 2x . (x + 7)x² + 3x + 3x + 9 = 2x² + 14xx² + 6x + 9 = 2x² + 14xx² - 2x² + 6x - 14x + 9- x² - 8x + 9 = 0Δ = b² - 4 . a . cΔ = (- 8)² - 4 . (- 1) . 9Δ = 64 + 36Δ = 100
x = (- b ± √Δ)/2 . ax = (- (- 8) ± √100)/2 . (- 1)x = (8 ± 10)/- 2
x' = (8 + 10)/- 2x' = 18/- 2x' = - 18/2x' = - 9
x'' = (8 - 10)/- 2x'' = - 2/- 2x'' = 2/2x'' = 1