2c^2-c-15=0

Solution for 2c^2-c-15=0 equation:

Simplifying
2c2 + -1c + -15 = 0

Reorder the terms:
-15 + -1c + 2c2 = 0

Solving
-15 + -1c + 2c2 = 0

Solving for variable 'c'.

Factor a trinomial.
(-5 + -2c)(3 + -1c) = 0

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

Simplifying
-5 + -2c = 0

Solving
-5 + -2c = 0

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

Add '5' to each side of the equation.
-5 + 5 + -2c = 0 + 5

Combine like terms: -5 + 5 = 0
0 + -2c = 0 + 5
-2c = 0 + 5

Combine like terms: 0 + 5 = 5
-2c = 5

Divide each side by '-2'.
c = -2.5

Simplifying
c = -2.5
Subproblem 2
Set the factor '(3 + -1c)' equal to zero and attempt to solve:

Simplifying
3 + -1c = 0

Solving
3 + -1c = 0

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

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

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

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

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

Simplifying
c = 3
Solution
c = {-2.5, 3}