Let x be the unknown number
2x +7 = 39
2x+7-7 = 39-7
2x = 32
2x/2 = 32/2
x=16
You use the balance method to solve. First, you cancel the +7 by subtracting the 7 ON BOTH SIDES to balance the equation.. After that, you are left with 2x, where you will need to isolate the x by dividing by 2 ON BOTH SIDES to balance it.
Hope this helps
