Question

12) 3x² + 5x = -x – 9 + 2x²
13) 4 + x ( x - 4) = x
14) x ( x + 3) – 40 = 0
15) (x - 5)² = 1
FAÇA O CALCULO DESSAS EQUAÇÕES COMPLETO PASSO A PASSO

Answer 1

Explicação passo a passo:

12) 3x² + 5x = -x – 9 + 2x²

3x² + 5x + x + 9 - 2x² = 0

x² + 5x + x + 9 = 0  

x² + 6x + 9 = 0  

=>  (x+3)² = 0

     x + 3 = 0

     x = -3

13) 4 + x ( x - 4) = x

4 + x² - 4x = x

4 + x² - 4x - x = 0

4 + x² - 5x = 0

x² - 5x + 4 = 0

x² - x - 4x + 4 = 0

x.(x-1) - 4x + 4 = 0

x.(x-1) - 4(x-1) = 0

(x-1).(x-4) = 0

x - 1 = 0    => x = 1

x - 4 = 0   => x = 4

14) x ( x + 3) – 40 = 0

x² + 3x - 40 = 0

x² + 8x - 5x - 40 = 0

x.(x + 8) - 5(x + 8) = 0

(x + 8) . (x - 5) = 0

x + 8 = 0   =>  x = -8

x - 5 = 0    =>  x = 5

15) (x - 5)² = ±1

x - 5 = -1     =>     x = 4

x - 5 = 1      =>     x = 6