30=b(b-7)

Solution for 30=b(b-7) equation:

Simplifying
30 = b(b + -7)

Reorder the terms:
30 = b(-7 + b)
30 = (-7 * b + b * b)
30 = (-7b + b2)

Solving
30 = -7b + b2

Solving for variable 'b'.

Reorder the terms:
30 + 7b + -1b2 = -7b + 7b + b2 + -1b2

Combine like terms: -7b + 7b = 0
30 + 7b + -1b2 = 0 + b2 + -1b2
30 + 7b + -1b2 = b2 + -1b2

Combine like terms: b2 + -1b2 = 0
30 + 7b + -1b2 = 0

Factor a trinomial.
(10 + -1b)(3 + 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 '(3 + b)' equal to zero and attempt to solve:

Simplifying
3 + b = 0

Solving
3 + b = 0

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

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

Combine like terms: 3 + -3 = 0
0 + b = 0 + -3
b = 0 + -3

Combine like terms: 0 + -3 = -3
b = -3

Simplifying
b = -3
Solution
b = {10, -3}