Question

Help on number 7 please

Answer 1

2(x + 7) = 20...distribute the 2 through the parenthesis
2x + 14 = 20...subtract 14 from each side
2x = 20 - 14
2x = 6...divide both sides by 2
x = 6/2
x = 3 <===

Answer 2

         2 (x + 7)  =  20

The '2' operates on everything inside the parentheses.
So if you want to remove the parentheses ... a good idea ..
you have to change it to      2x + 14.

Now the equation says

                                     2x + 14  =  20
Subtract 14
from each side:              2x          =   6

Divide each side by 2:      x          =   3