40=b(b-6)

Solution for 40=b(b-6) equation:

Simplifying
40 = b(b + -6)

Reorder the terms:
40 = b(-6 + b)
40 = (-6 * b + b * b)
40 = (-6b + b2)

Solving
40 = -6b + b2

Solving for variable 'b'.

Reorder the terms:
40 + 6b + -1b2 = -6b + 6b + b2 + -1b2

Combine like terms: -6b + 6b = 0
40 + 6b + -1b2 = 0 + b2 + -1b2
40 + 6b + -1b2 = b2 + -1b2

Combine like terms: b2 + -1b2 = 0
40 + 6b + -1b2 = 0

Factor a trinomial.
(10 + -1b)(4 + b) = 0

Subproblem 1
Set the factor '(10 + -1b)' equal to zero and attempt to solve:

Simplifying
10 + -1b = 0

Solving
10 + -1b = 0

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

Add '-10' to each side of the equation.
10 + -10 + -1b = 0 + -10

Combine like terms: 10 + -10 = 0
0 + -1b = 0 + -10
-1b = 0 + -10

Combine like terms: 0 + -10 = -10
-1b = -10

Divide each side by '-1'.
b = 10

Simplifying
b = 10
Subproblem 2
Set the factor '(4 + b)' equal to zero and attempt to solve:

Simplifying
4 + b = 0

Solving
4 + b = 0

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

Add '-4' to each side of the equation.
4 + -4 + b = 0 + -4

Combine like terms: 4 + -4 = 0
0 + b = 0 + -4
b = 0 + -4

Combine like terms: 0 + -4 = -4
b = -4

Simplifying
b = -4
Solution
b = {10, -4}