(9a-2)(a+9)=

Solution for (9a-2)(a+9)= equation:

Simplifying
(9a + -2)(a + 9) = 0

Reorder the terms:
(-2 + 9a)(a + 9) = 0

Reorder the terms:
(-2 + 9a)(9 + a) = 0

Multiply (-2 + 9a) * (9 + a)
(-2(9 + a) + 9a * (9 + a)) = 0
((9 * -2 + a * -2) + 9a * (9 + a)) = 0
((-18 + -2a) + 9a * (9 + a)) = 0
(-18 + -2a + (9 * 9a + a * 9a)) = 0
(-18 + -2a + (81a + 9a2)) = 0

Combine like terms: -2a + 81a = 79a
(-18 + 79a + 9a2) = 0

Solving
-18 + 79a + 9a2 = 0

Solving for variable 'a'.

Factor a trinomial.
(-9 + -1a)(2 + -9a) = 0

Subproblem 1
Set the factor '(-9 + -1a)' equal to zero and attempt to solve:

Simplifying
-9 + -1a = 0

Solving
-9 + -1a = 0

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

Add '9' to each side of the equation.
-9 + 9 + -1a = 0 + 9

Combine like terms: -9 + 9 = 0
0 + -1a = 0 + 9
-1a = 0 + 9

Combine like terms: 0 + 9 = 9
-1a = 9

Divide each side by '-1'.
a = -9

Simplifying
a = -9
Subproblem 2
Set the factor '(2 + -9a)' equal to zero and attempt to solve:

Simplifying
2 + -9a = 0

Solving
2 + -9a = 0

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

Add '-2' to each side of the equation.
2 + -2 + -9a = 0 + -2

Combine like terms: 2 + -2 = 0
0 + -9a = 0 + -2
-9a = 0 + -2

Combine like terms: 0 + -2 = -2
-9a = -2

Divide each side by '-9'.
a = 0.2222222222

Simplifying
a = 0.2222222222
Solution
a = {-9, 0.2222222222}