a^2+7a=120

Solution for a^2+7a=120 equation:

Simplifying
a2 + 7a = 120

Reorder the terms:
7a + a2 = 120

Solving
7a + a2 = 120

Solving for variable 'a'.

Reorder the terms:
-120 + 7a + a2 = 120 + -120

Combine like terms: 120 + -120 = 0
-120 + 7a + a2 = 0

Factor a trinomial.
(-15 + -1a)(8 + -1a) = 0

Subproblem 1
Set the factor '(-15 + -1a)' equal to zero and attempt to solve:

Simplifying
-15 + -1a = 0

Solving
-15 + -1a = 0

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

Add '15' to each side of the equation.
-15 + 15 + -1a = 0 + 15

Combine like terms: -15 + 15 = 0
0 + -1a = 0 + 15
-1a = 0 + 15

Combine like terms: 0 + 15 = 15
-1a = 15

Divide each side by '-1'.
a = -15

Simplifying
a = -15
Subproblem 2
Set the factor '(8 + -1a)' equal to zero and attempt to solve:

Simplifying
8 + -1a = 0

Solving
8 + -1a = 0

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

Add '-8' to each side of the equation.
8 + -8 + -1a = 0 + -8

Combine like terms: 8 + -8 = 0
0 + -1a = 0 + -8
-1a = 0 + -8

Combine like terms: 0 + -8 = -8
-1a = -8

Divide each side by '-1'.
a = 8

Simplifying
a = 8
Solution
a = {-15, 8}