40=a(a-6)

Solution for 40=a(a-6) equation:

Simplifying
40 = a(a + -6)

Reorder the terms:
40 = a(-6 + a)
40 = (-6 * a + a * a)
40 = (-6a + a2)

Solving
40 = -6a + a2

Solving for variable 'a'.

Reorder the terms:
40 + 6a + -1a2 = -6a + 6a + a2 + -1a2

Combine like terms: -6a + 6a = 0
40 + 6a + -1a2 = 0 + a2 + -1a2
40 + 6a + -1a2 = a2 + -1a2

Combine like terms: a2 + -1a2 = 0
40 + 6a + -1a2 = 0

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

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

Simplifying
10 + -1a = 0

Solving
10 + -1a = 0

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

Add '-10' to each side of the equation.
10 + -10 + -1a = 0 + -10

Combine like terms: 10 + -10 = 0
0 + -1a = 0 + -10
-1a = 0 + -10

Combine like terms: 0 + -10 = -10
-1a = -10

Divide each side by '-1'.
a = 10

Simplifying
a = 10
Subproblem 2
Set the factor '(4 + a)' equal to zero and attempt to solve:

Simplifying
4 + a = 0

Solving
4 + a = 0

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

Add '-4' to each side of the equation.
4 + -4 + a = 0 + -4

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

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

Simplifying
a = -4
Solution
a = {10, -4}