(3a-3)(a+5)=

Solution for (3a-3)(a+5)= equation:

Simplifying
(3a + -3)(a + 5) = 0

Reorder the terms:
(-3 + 3a)(a + 5) = 0

Reorder the terms:
(-3 + 3a)(5 + a) = 0

Multiply (-3 + 3a) * (5 + a)
(-3(5 + a) + 3a * (5 + a)) = 0
((5 * -3 + a * -3) + 3a * (5 + a)) = 0
((-15 + -3a) + 3a * (5 + a)) = 0
(-15 + -3a + (5 * 3a + a * 3a)) = 0
(-15 + -3a + (15a + 3a2)) = 0

Combine like terms: -3a + 15a = 12a
(-15 + 12a + 3a2) = 0

Solving
-15 + 12a + 3a2 = 0

Solving for variable 'a'.

Factor out the Greatest Common Factor (GCF), '3'.
3(-5 + 4a + a2) = 0

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

Ignore the factor 3.
Subproblem 1
Set the factor '(-5 + -1a)' equal to zero and attempt to solve:

Simplifying
-5 + -1a = 0

Solving
-5 + -1a = 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 + -1a = 0 + 5

Combine like terms: -5 + 5 = 0
0 + -1a = 0 + 5
-1a = 0 + 5

Combine like terms: 0 + 5 = 5
-1a = 5

Divide each side by '-1'.
a = -5

Simplifying
a = -5
Subproblem 2
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
Solution
a = {-5, 1}