(4a+4)(5a+5a-9)=

Solution for (4a+4)(5a+5a-9)= equation:

Simplifying
(4a + 4)(5a + 5a + -9) = 0

Reorder the terms:
(4 + 4a)(5a + 5a + -9) = 0

Reorder the terms:
(4 + 4a)(-9 + 5a + 5a) = 0

Combine like terms: 5a + 5a = 10a
(4 + 4a)(-9 + 10a) = 0

Multiply (4 + 4a) * (-9 + 10a)
(4(-9 + 10a) + 4a * (-9 + 10a)) = 0
((-9 * 4 + 10a * 4) + 4a * (-9 + 10a)) = 0
((-36 + 40a) + 4a * (-9 + 10a)) = 0
(-36 + 40a + (-9 * 4a + 10a * 4a)) = 0
(-36 + 40a + (-36a + 40a2)) = 0

Combine like terms: 40a + -36a = 4a
(-36 + 4a + 40a2) = 0

Solving
-36 + 4a + 40a2 = 0

Solving for variable 'a'.

Factor out the Greatest Common Factor (GCF), '4'.
4(-9 + a + 10a2) = 0

Factor a trinomial.
4((-1 + -1a)(9 + -10a)) = 0

Ignore the factor 4.
Subproblem 1
Set the factor '(-1 + -1a)' equal to zero and attempt to solve:

Simplifying
-1 + -1a = 0

Solving
-1 + -1a = 0

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

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

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

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

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

Simplifying
a = -1
Subproblem 2
Set the factor '(9 + -10a)' equal to zero and attempt to solve:

Simplifying
9 + -10a = 0

Solving
9 + -10a = 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 + -10a = 0 + -9

Combine like terms: 9 + -9 = 0
0 + -10a = 0 + -9
-10a = 0 + -9

Combine like terms: 0 + -9 = -9
-10a = -9

Divide each side by '-10'.
a = 0.9

Simplifying
a = 0.9
Solution
a = {-1, 0.9}