So to figure this out, we can substitute integers for the blanks, so let's sub in x and y:
6 (1 + 2) = (x) + (2y)
so:
x = 6 + 12 - 2y
x = 18 - 2y
6 (1 + 2) = (18-2y) + (2y)
6 + 12 = 18
18 = 18
So we know that this equation works!
(18 is not the answer but is the result of the equation being proven true)