(c-9)(c+64)=0

Solution for (c-9)(c+64)=0 equation:

Simplifying
(c + -9)(c + 64) = 0

Reorder the terms:
(-9 + c)(c + 64) = 0

Reorder the terms:
(-9 + c)(64 + c) = 0

Multiply (-9 + c) * (64 + c)
(-9(64 + c) + c(64 + c)) = 0
((64 * -9 + c * -9) + c(64 + c)) = 0
((-576 + -9c) + c(64 + c)) = 0
(-576 + -9c + (64 * c + c * c)) = 0
(-576 + -9c + (64c + c2)) = 0

Combine like terms: -9c + 64c = 55c
(-576 + 55c + c2) = 0

Solving
-576 + 55c + c2 = 0

Solving for variable 'c'.

Factor a trinomial.
(-64 + -1c)(9 + -1c) = 0

Subproblem 1
Set the factor '(-64 + -1c)' equal to zero and attempt to solve:

Simplifying
-64 + -1c = 0

Solving
-64 + -1c = 0

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

Add '64' to each side of the equation.
-64 + 64 + -1c = 0 + 64

Combine like terms: -64 + 64 = 0
0 + -1c = 0 + 64
-1c = 0 + 64

Combine like terms: 0 + 64 = 64
-1c = 64

Divide each side by '-1'.
c = -64

Simplifying
c = -64
Subproblem 2
Set the factor '(9 + -1c)' equal to zero and attempt to solve:

Simplifying
9 + -1c = 0

Solving
9 + -1c = 0

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

Add '-9' to each side of the equation.
9 + -9 + -1c = 0 + -9

Combine like terms: 9 + -9 = 0
0 + -1c = 0 + -9
-1c = 0 + -9

Combine like terms: 0 + -9 = -9
-1c = -9

Divide each side by '-1'.
c = 9

Simplifying
c = 9
Solution
c = {-64, 9}