=9a-4(2a+5)

Solution for =9a-4(2a+5) equation:

Simplifying
0 = 9a + -4(2a + 5)

Reorder the terms:
0 = 9a + -4(5 + 2a)
0 = 9a + (5 * -4 + 2a * -4)
0 = 9a + (-20 + -8a)

Reorder the terms:
0 = -20 + 9a + -8a

Combine like terms: 9a + -8a = 1a
0 = -20 + 1a

Solving
0 = -20 + 1a

Solving for variable 'a'.

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

Add '-1a' to each side of the equation.
0 + -1a = -20 + 1a + -1a
Remove the zero:
-1a = -20 + 1a + -1a

Combine like terms: 1a + -1a = 0
-1a = -20 + 0
-1a = -20

Divide each side by '-1'.
a = 20

Simplifying
a = 20