21a^2+48a-45=

Solution for 21a^2+48a-45= equation:

Simplifying
21a2 + 48a + -45 = 0

Reorder the terms:
-45 + 48a + 21a2 = 0

Solving
-45 + 48a + 21a2 = 0

Solving for variable 'a'.

Factor out the Greatest Common Factor (GCF), '3'.
3(-15 + 16a + 7a2) = 0

Factor a trinomial.
3((-3 + -1a)(5 + -7a)) = 0

Ignore the factor 3.
Subproblem 1
Set the factor '(-3 + -1a)' equal to zero and attempt to solve:

Simplifying
-3 + -1a = 0

Solving
-3 + -1a = 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 + -1a = 0 + 3

Combine like terms: -3 + 3 = 0
0 + -1a = 0 + 3
-1a = 0 + 3

Combine like terms: 0 + 3 = 3
-1a = 3

Divide each side by '-1'.
a = -3

Simplifying
a = -3
Subproblem 2
Set the factor '(5 + -7a)' equal to zero and attempt to solve:

Simplifying
5 + -7a = 0

Solving
5 + -7a = 0

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

Add '-5' to each side of the equation.
5 + -5 + -7a = 0 + -5

Combine like terms: 5 + -5 = 0
0 + -7a = 0 + -5
-7a = 0 + -5

Combine like terms: 0 + -5 = -5
-7a = -5

Divide each side by '-7'.
a = 0.7142857143

Simplifying
a = 0.7142857143
Solution
a = {-3, 0.7142857143}