guilhermef15 Olá Erick,

a) 5 x - 9 = - x + 45
5x +x = 45 +9
6x=54
x=54/6
x=9.

b)5 x + 2 x = 73 - 10
7x=63
x=63/7
x=9.

c) 4 x - x = 19 + 8
3x=27
x=27/3
x=9

d) 7 x - 19 = - 2 x + 62
7x + 2x = 62 + 19
9x=81
x=81/9
x=9.

Espero ter ajudado!

Jayrobeys Boa noite

veja:

a)

5x - 9 = - x + 45

5x + x = 45 + 9 

6x = 54

x = 54 / 6

x = 9 

b)

5x + 2x = 73 - 10

7x = 63

x = 63 / 7

x = 9

c)

4x - x = 19 + 8 

3x = 27

x = 27 / 3

x = 9 

d)

7x - 19 = - 2x + 62

7x + 2x = 62 + 19

9x = 81

x = 81 / 9

x = 9