8.

2x + 5 = 11

 

First subtract 5 from both sides.

2x

+

5

=

11

-

5

-

5

2x

=

6

 

Then divide both sides by 2

 

2x/2 = 6/2

 

x = 3

 

Check

 

2(3) + 5 = 11

6 + 5 = 11