a(4a-15)=25

Solution for a(4a-15)=25 equation:

Simplifying
a(4a + -15) = 25

Reorder the terms:
a(-15 + 4a) = 25
(-15 * a + 4a * a) = 25
(-15a + 4a2) = 25

Solving
-15a + 4a2 = 25

Solving for variable 'a'.

Reorder the terms:
-25 + -15a + 4a2 = 25 + -25

Combine like terms: 25 + -25 = 0
-25 + -15a + 4a2 = 0

Factor a trinomial.
(-5 + -4a)(5 + -1a) = 0

Subproblem 1
Set the factor '(-5 + -4a)' equal to zero and attempt to solve:

Simplifying
-5 + -4a = 0

Solving
-5 + -4a = 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 + -4a = 0 + 5

Combine like terms: -5 + 5 = 0
0 + -4a = 0 + 5
-4a = 0 + 5

Combine like terms: 0 + 5 = 5
-4a = 5

Divide each side by '-4'.
a = -1.25

Simplifying
a = -1.25
Subproblem 2
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
Solution
a = {-1.25, 5}