(3-z)(5z-4)=0

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

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

Reorder the terms:
(3 + -1z)(-4 + 5z) = 0

Multiply (3 + -1z) * (-4 + 5z)
(3(-4 + 5z) + -1z * (-4 + 5z)) = 0
((-4 * 3 + 5z * 3) + -1z * (-4 + 5z)) = 0
((-12 + 15z) + -1z * (-4 + 5z)) = 0
(-12 + 15z + (-4 * -1z + 5z * -1z)) = 0
(-12 + 15z + (4z + -5z2)) = 0

Combine like terms: 15z + 4z = 19z
(-12 + 19z + -5z2) = 0

Solving
-12 + 19z + -5z2 = 0

Solving for variable 'z'.

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

Subproblem 1
Set the factor '(-3 + z)' equal to zero and attempt to solve:

Simplifying
-3 + z = 0

Solving
-3 + z = 0

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

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

Combine like terms: -3 + 3 = 0
0 + z = 0 + 3
z = 0 + 3

Combine like terms: 0 + 3 = 3
z = 3

Simplifying
z = 3
Subproblem 2
Set the factor '(4 + -5z)' equal to zero and attempt to solve:

Simplifying
4 + -5z = 0

Solving
4 + -5z = 0

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

Add '-4' to each side of the equation.
4 + -4 + -5z = 0 + -4

Combine like terms: 4 + -4 = 0
0 + -5z = 0 + -4
-5z = 0 + -4

Combine like terms: 0 + -4 = -4
-5z = -4

Divide each side by '-5'.
z = 0.8

Simplifying
z = 0.8
Solution
z = {3, 0.8}