Question

Resolva as equações do 2o grau: (Valor 1,0)
a) 5x2 - 28x = 0
b) x2 - 4 = 0
c) 18x2 - 36 = 0
d) 10x2 + 72x – 64 = 0
e) 2x2 = - 12x - 18

Answer 1

Explicação passo-a-passo:

A)

5 × 2 - 28x = 0

10 - 28x = 0

- 28x = -10

x = 5/14

B)

x2 - 4 = 0

2x - 4 = 0

2x = 4

x = 4 ÷ 2

x = 2

C)

18 x2 - 36 = 0

36x - 36 = 0

36x = 36

x = 36 ÷ 36

x = 1

D)

10 x2 + 72x - 64 = 0

20x + 72x -64 = 0

92x - 64 = 0

92x = 64

x = 16/23

E)

2 x 2 = - 12x (- 18)

4x = -12x (-18)

4x = 216

x = 216 ÷ 4

x = 54