30=a(a-7)

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

Simplifying
30 = a(a + -7)

Reorder the terms:
30 = a(-7 + a)
30 = (-7 * a + a * a)
30 = (-7a + a2)

Solving
30 = -7a + a2

Solving for variable 'a'.

Reorder the terms:
30 + 7a + -1a2 = -7a + 7a + a2 + -1a2

Combine like terms: -7a + 7a = 0
30 + 7a + -1a2 = 0 + a2 + -1a2
30 + 7a + -1a2 = a2 + -1a2

Combine like terms: a2 + -1a2 = 0
30 + 7a + -1a2 = 0

Factor a trinomial.
(10 + -1a)(3 + a) = 0

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

Simplifying
10 + -1a = 0

Solving
10 + -1a = 0

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

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

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

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

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

Simplifying
a = 10
Subproblem 2
Set the factor '(3 + a)' equal to zero and attempt to solve:

Simplifying
3 + a = 0

Solving
3 + a = 0

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

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

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

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

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