5a^2-21a+16=-2

Solution for 5a^2-21a+16=-2 equation:

Simplifying
5a2 + -21a + 16 = -2

Reorder the terms:
16 + -21a + 5a2 = -2

Solving
16 + -21a + 5a2 = -2

Solving for variable 'a'.

Reorder the terms:
16 + 2 + -21a + 5a2 = -2 + 2

Combine like terms: 16 + 2 = 18
18 + -21a + 5a2 = -2 + 2

Combine like terms: -2 + 2 = 0
18 + -21a + 5a2 = 0

Factor a trinomial.
(6 + -5a)(3 + -1a) = 0

Subproblem 1
Set the factor '(6 + -5a)' equal to zero and attempt to solve:

Simplifying
6 + -5a = 0

Solving
6 + -5a = 0

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

Add '-6' to each side of the equation.
6 + -6 + -5a = 0 + -6

Combine like terms: 6 + -6 = 0
0 + -5a = 0 + -6
-5a = 0 + -6

Combine like terms: 0 + -6 = -6
-5a = -6

Divide each side by '-5'.
a = 1.2

Simplifying
a = 1.2
Subproblem 2
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
Solution
a = {1.2, 3}