225-20b-5b^2=

Solution for 225-20b-5b^2= equation:

Simplifying
225 + -20b + -5b2 = 0

Solving
225 + -20b + -5b2 = 0

Solving for variable 'b'.

Factor out the Greatest Common Factor (GCF), '5'.
5(45 + -4b + -1b2) = 0

Factor a trinomial.
5((5 + -1b)(9 + b)) = 0

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

Simplifying
5 + -1b = 0

Solving
5 + -1b = 0

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

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

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

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

Divide each side by '-1'.
b = 5

Simplifying
b = 5
Subproblem 2
Set the factor '(9 + b)' equal to zero and attempt to solve:

Simplifying
9 + b = 0

Solving
9 + b = 0

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

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

Combine like terms: 9 + -9 = 0
0 + b = 0 + -9
b = 0 + -9

Combine like terms: 0 + -9 = -9
b = -9

Simplifying
b = -9
Solution
b = {5, -9}