39-7x=-4(7x+7)+4 given
39-7x=(-28x+28)+4 distribute
35-7x=-28x+28 subtract both sides (4)
7-7x=-28x subtract both sides (28)
7=-21x subtract both sides (7x)
x=-3 divide both sides (7)
i hope this helps!
yoy don't need to keep those extra comments next to the equations, they are there for you to understand it better!
also make sure to remember the negative signs <3