-12=4(y+2(y-9))

Solution for -12=4(y+2(y-9)) equation:

Simplifying
-12 = 4(y + 2(y + -9))

Reorder the terms:
-12 = 4(y + 2(-9 + y))
-12 = 4(y + (-9 * 2 + y * 2))
-12 = 4(y + (-18 + 2y))

Reorder the terms:
-12 = 4(-18 + y + 2y)

Combine like terms: y + 2y = 3y
-12 = 4(-18 + 3y)
-12 = (-18 * 4 + 3y * 4)
-12 = (-72 + 12y)

Solving
-12 = -72 + 12y

Solving for variable 'y'.

Move all terms containing y to the left, all other terms to the right.

Add '-12y' to each side of the equation.
-12 + -12y = -72 + 12y + -12y

Combine like terms: 12y + -12y = 0
-12 + -12y = -72 + 0
-12 + -12y = -72

Add '12' to each side of the equation.
-12 + 12 + -12y = -72 + 12

Combine like terms: -12 + 12 = 0
0 + -12y = -72 + 12
-12y = -72 + 12

Combine like terms: -72 + 12 = -60
-12y = -60

Divide each side by '-12'.
y = 5

Simplifying
y = 5