l(l-15)=126

Solution for l(l-15)=126 equation:

Simplifying
l(l + -15) = 126

Reorder the terms:
l(-15 + l) = 126
(-15 * l + l * l) = 126
(-15l + l2) = 126

Solving
-15l + l2 = 126

Solving for variable 'l'.

Reorder the terms:
-126 + -15l + l2 = 126 + -126

Combine like terms: 126 + -126 = 0
-126 + -15l + l2 = 0

Factor a trinomial.
(-6 + -1l)(21 + -1l) = 0

Subproblem 1
Set the factor '(-6 + -1l)' equal to zero and attempt to solve:

Simplifying
-6 + -1l = 0

Solving
-6 + -1l = 0

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

Add '6' to each side of the equation.
-6 + 6 + -1l = 0 + 6

Combine like terms: -6 + 6 = 0
0 + -1l = 0 + 6
-1l = 0 + 6

Combine like terms: 0 + 6 = 6
-1l = 6

Divide each side by '-1'.
l = -6

Simplifying
l = -6
Subproblem 2
Set the factor '(21 + -1l)' equal to zero and attempt to solve:

Simplifying
21 + -1l = 0

Solving
21 + -1l = 0

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

Add '-21' to each side of the equation.
21 + -21 + -1l = 0 + -21

Combine like terms: 21 + -21 = 0
0 + -1l = 0 + -21
-1l = 0 + -21

Combine like terms: 0 + -21 = -21
-1l = -21

Divide each side by '-1'.
l = 21

Simplifying
l = 21
Solution
l = {-6, 21}