-15z^2+45z+60=0

Solution for -15z^2+45z+60=0 equation:

Simplifying
-15z2 + 45z + 60 = 0

Reorder the terms:
60 + 45z + -15z2 = 0

Solving
60 + 45z + -15z2 = 0

Solving for variable 'z'.

Factor out the Greatest Common Factor (GCF), '15'.
15(4 + 3z + -1z2) = 0

Factor a trinomial.
15((4 + -1z)(1 + z)) = 0

Ignore the factor 15.
Subproblem 1
Set the factor '(4 + -1z)' equal to zero and attempt to solve:

Simplifying
4 + -1z = 0

Solving
4 + -1z = 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 + -1z = 0 + -4

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

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

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

Simplifying
z = 4
Subproblem 2
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
Solution
z = {4, -1}