Question

(x+3)(x-3)=5x - 9
x²(x+2)= 0

Answer 1

(x+3)(x-3)=5x - 9

(x² - 3x + 3x - 9) = 5x - 9
(x²        0      - 9) = 5x - 9
x² - 9 = 5x - 9   ( igualar a ZERO)
x² - 9 - 5x + 9 = 0
x² - 5x - 9 + 9 = 0
x² -  5x     0    = 0
x² - 5x = 0

x(x - 5) = 0
x = 0
(x - 5) = 0
x - 5 = 0
x = + 5

assim
x' = 0
x" = 5

x²(x+2)= 0
x² = 0
x = + - √0     (√0 = 0)
x =  + - 0  
(x + 2) = 0
x + 2 = 0x = - 2

assim
x' e x" = 0
x'" = - 2