Question

2(×+3)(×-3)-6×=-×(×+3)

Answer 1

Explicação passo-a-passo:

2 . (x² -3x +3x - 9) - 6x = x² +3x

2 . (x² -9) - 6x =- x² -3x

2x² - 18 - 6x = -x² - 3x

2x² + x² - 6x +3x - 18=0

3x² - 3x - 18=0 (÷3)

x² - x - 6=0

∆= (-1)² - 4.1.(-6)

∆= 1 + 24

∆= 25

x = - (-1) ±√25/2.1

x = 1 ±5 /2

x1= 1+5/2= 6/2= 3

x2= 1-5/2= -4/2= -2

S= { - 2 , 3}