15h^2-42h-9=0

Solution for 15h^2-42h-9=0 equation:

Simplifying
15h2 + -42h + -9 = 0

Reorder the terms:
-9 + -42h + 15h2 = 0

Solving
-9 + -42h + 15h2 = 0

Solving for variable 'h'.

Factor out the Greatest Common Factor (GCF), '3'.
3(-3 + -14h + 5h2) = 0

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

Ignore the factor 3.
Subproblem 1
Set the factor '(-1 + -5h)' equal to zero and attempt to solve:

Simplifying
-1 + -5h = 0

Solving
-1 + -5h = 0

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

Add '1' to each side of the equation.
-1 + 1 + -5h = 0 + 1

Combine like terms: -1 + 1 = 0
0 + -5h = 0 + 1
-5h = 0 + 1

Combine like terms: 0 + 1 = 1
-5h = 1

Divide each side by '-5'.
h = -0.2

Simplifying
h = -0.2
Subproblem 2
Set the factor '(3 + -1h)' equal to zero and attempt to solve:

Simplifying
3 + -1h = 0

Solving
3 + -1h = 0

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

Add '-3' to each side of the equation.
3 + -3 + -1h = 0 + -3

Combine like terms: 3 + -3 = 0
0 + -1h = 0 + -3
-1h = 0 + -3

Combine like terms: 0 + -3 = -3
-1h = -3

Divide each side by '-1'.
h = 3

Simplifying
h = 3
Solution
h = {-0.2, 3}