Question

Encontre as raízes das seguintes equações, para U=R:

Exemplo:
2 (x +2) + 4 (x - 3) = 64
2x + 4 + 4x - 12 = 64
2x+ 4x + 4-12 = 64
6x8 = 64
6x = 64 + 8
6x = 72
x = 12


a)10 ( x + 2)-5(x - 2) = 70

b)5(x + 2) - 11 = 2(3x - 2)

c)7 ( 2 + x) = 5(x - 1,2) + 35

Answer 1

Resposta:

a)10(x + 1) – 5(x – 2) = 70

10x + 10 - 5x + 10 = 70

10x - 5x = 70 - 10 - 10

5x = 50

x = 50/5

x = 10

S = {10}

b)5(x + 2) – 13 = 2(3x – 1)

5x + 10 - 13 = 6x - 2

5x - 6x = - 2 - 10 + 13

- x = 1 .(-1)

x = - 1

S = {-1}

c)7(2 + x) = 5(x – 1,2) + 35

14 + 7x = 5x - 6 + 35

7x - 5x = - 6 + 35 - 14

2x = 15

x = 15/2

x = 7,5

S = {7,5}