The given equation is better written as
-10 = 1/4*(8y-12)
The first way of the solution is as follows:
Distribute 1/4 to the inside equation of the parenthesis.
-10 = 2y - 3
2y = -10 + 3 = -7
y = -7/2 = -3.5
The second way of the solution is as follows:
Cross-multiply the denominator a the right side to the left side.
-10*4 = 8y - 12
-40 = 8y - 12
8y = -40 + 12 = -28
y = -28/8 = -3.5