(3+5y)(4-y)=0

Solution for (3+5y)(4-y)=0 equation:

Simplifying
(3 + 5y)(4 + -1y) = 0

Multiply (3 + 5y) * (4 + -1y)
(3(4 + -1y) + 5y * (4 + -1y)) = 0
((4 * 3 + -1y * 3) + 5y * (4 + -1y)) = 0
((12 + -3y) + 5y * (4 + -1y)) = 0
(12 + -3y + (4 * 5y + -1y * 5y)) = 0
(12 + -3y + (20y + -5y2)) = 0

Combine like terms: -3y + 20y = 17y
(12 + 17y + -5y2) = 0

Solving
12 + 17y + -5y2 = 0

Solving for variable 'y'.

Factor a trinomial.
(4 + -1y)(3 + 5y) = 0

Subproblem 1
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
Subproblem 2
Set the factor '(3 + 5y)' equal to zero and attempt to solve:

Simplifying
3 + 5y = 0

Solving
3 + 5y = 0

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

Add '-3' to each side of the equation.
3 + -3 + 5y = 0 + -3

Combine like terms: 3 + -3 = 0
0 + 5y = 0 + -3
5y = 0 + -3

Combine like terms: 0 + -3 = -3
5y = -3

Divide each side by '5'.
y = -0.6

Simplifying
y = -0.6
Solution
y = {4, -0.6}