a^2-20a-800=0

Solution for a^2-20a-800=0 equation:

Simplifying
a2 + -20a + -800 = 0

Reorder the terms:
-800 + -20a + a2 = 0

Solving
-800 + -20a + a2 = 0

Solving for variable 'a'.

Factor a trinomial.
(-20 + -1a)(40 + -1a) = 0

Subproblem 1
Set the factor '(-20 + -1a)' equal to zero and attempt to solve:

Simplifying
-20 + -1a = 0

Solving
-20 + -1a = 0

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

Add '20' to each side of the equation.
-20 + 20 + -1a = 0 + 20

Combine like terms: -20 + 20 = 0
0 + -1a = 0 + 20
-1a = 0 + 20

Combine like terms: 0 + 20 = 20
-1a = 20

Divide each side by '-1'.
a = -20

Simplifying
a = -20
Subproblem 2
Set the factor '(40 + -1a)' equal to zero and attempt to solve:

Simplifying
40 + -1a = 0

Solving
40 + -1a = 0

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

Add '-40' to each side of the equation.
40 + -40 + -1a = 0 + -40

Combine like terms: 40 + -40 = 0
0 + -1a = 0 + -40
-1a = 0 + -40

Combine like terms: 0 + -40 = -40
-1a = -40

Divide each side by '-1'.
a = 40

Simplifying
a = 40
Solution
a = {-20, 40}