(y-4)(7y+8)=0

Solution for (y-4)(7y+8)=0 equation:

Simplifying
(y + -4)(7y + 8) = 0

Reorder the terms:
(-4 + y)(7y + 8) = 0

Reorder the terms:
(-4 + y)(8 + 7y) = 0

Multiply (-4 + y) * (8 + 7y)
(-4(8 + 7y) + y(8 + 7y)) = 0
((8 * -4 + 7y * -4) + y(8 + 7y)) = 0
((-32 + -28y) + y(8 + 7y)) = 0
(-32 + -28y + (8 * y + 7y * y)) = 0
(-32 + -28y + (8y + 7y2)) = 0

Combine like terms: -28y + 8y = -20y
(-32 + -20y + 7y2) = 0

Solving
-32 + -20y + 7y2 = 0

Solving for variable 'y'.

Factor a trinomial.
(-8 + -7y)(4 + -1y) = 0

Subproblem 1
Set the factor '(-8 + -7y)' equal to zero and attempt to solve:

Simplifying
-8 + -7y = 0

Solving
-8 + -7y = 0

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

Add '8' to each side of the equation.
-8 + 8 + -7y = 0 + 8

Combine like terms: -8 + 8 = 0
0 + -7y = 0 + 8
-7y = 0 + 8

Combine like terms: 0 + 8 = 8
-7y = 8

Divide each side by '-7'.
y = -1.142857143

Simplifying
y = -1.142857143
Subproblem 2
Set the factor '(4 + -1y)' equal to zero and attempt to solve:

Simplifying
4 + -1y = 0

Solving
4 + -1y = 0

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

Add '-4' to each side of the equation.
4 + -4 + -1y = 0 + -4

Combine like terms: 4 + -4 = 0
0 + -1y = 0 + -4
-1y = 0 + -4

Combine like terms: 0 + -4 = -4
-1y = -4

Divide each side by '-1'.
y = 4

Simplifying
y = 4
Solution
y = {-1.142857143, 4}