3l^2-7l-20=0

Solution for 3l^2-7l-20=0 equation:

Simplifying
3l2 + -7l + -20 = 0

Reorder the terms:
-20 + -7l + 3l2 = 0

Solving
-20 + -7l + 3l2 = 0

Solving for variable 'l'.

Factor a trinomial.
(-5 + -3l)(4 + -1l) = 0

Subproblem 1
Set the factor '(-5 + -3l)' equal to zero and attempt to solve:

Simplifying
-5 + -3l = 0

Solving
-5 + -3l = 0

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

Add '5' to each side of the equation.
-5 + 5 + -3l = 0 + 5

Combine like terms: -5 + 5 = 0
0 + -3l = 0 + 5
-3l = 0 + 5

Combine like terms: 0 + 5 = 5
-3l = 5

Divide each side by '-3'.
l = -1.666666667

Simplifying
l = -1.666666667
Subproblem 2
Set the factor '(4 + -1l)' equal to zero and attempt to solve:

Simplifying
4 + -1l = 0

Solving
4 + -1l = 0

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

Add '-4' to each side of the equation.
4 + -4 + -1l = 0 + -4

Combine like terms: 4 + -4 = 0
0 + -1l = 0 + -4
-1l = 0 + -4

Combine like terms: 0 + -4 = -4
-1l = -4

Divide each side by '-1'.
l = 4

Simplifying
l = 4
Solution
l = {-1.666666667, 4}