-(5a+6)-3(a-9)=

Solution for -(5a+6)-3(a-9)= equation:

Simplifying
-1(5a + 6) + -3(a + -9) = 0

Reorder the terms:
-1(6 + 5a) + -3(a + -9) = 0
(6 * -1 + 5a * -1) + -3(a + -9) = 0
(-6 + -5a) + -3(a + -9) = 0

Reorder the terms:
-6 + -5a + -3(-9 + a) = 0
-6 + -5a + (-9 * -3 + a * -3) = 0
-6 + -5a + (27 + -3a) = 0

Reorder the terms:
-6 + 27 + -5a + -3a = 0

Combine like terms: -6 + 27 = 21
21 + -5a + -3a = 0

Combine like terms: -5a + -3a = -8a
21 + -8a = 0

Solving
21 + -8a = 0

Solving for variable 'a'.

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

Add '-21' to each side of the equation.
21 + -21 + -8a = 0 + -21

Combine like terms: 21 + -21 = 0
0 + -8a = 0 + -21
-8a = 0 + -21

Combine like terms: 0 + -21 = -21
-8a = -21

Divide each side by '-8'.
a = 2.625

Simplifying
a = 2.625