(5z+4)(1+z)=0

Solution for (5z+4)(1+z)=0 equation:

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

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

Multiply (4 + 5z) * (1 + z)
(4(1 + z) + 5z * (1 + z)) = 0
((1 * 4 + z * 4) + 5z * (1 + z)) = 0
((4 + 4z) + 5z * (1 + z)) = 0
(4 + 4z + (1 * 5z + z * 5z)) = 0
(4 + 4z + (5z + 5z2)) = 0

Combine like terms: 4z + 5z = 9z
(4 + 9z + 5z2) = 0

Solving
4 + 9z + 5z2 = 0

Solving for variable 'z'.

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

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

Simplifying
1 + z = 0

Solving
1 + z = 0

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

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

Combine like terms: 1 + -1 = 0
0 + z = 0 + -1
z = 0 + -1

Combine like terms: 0 + -1 = -1
z = -1

Simplifying
z = -1
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 = {-1, -0.8}