(-3a-9)+(4a+8)=

Solution for (-3a-9)+(4a+8)= equation:

Simplifying
(-3a + -9) + (4a + 8) = 0

Reorder the terms:
(-9 + -3a) + (4a + 8) = 0

Remove parenthesis around (-9 + -3a)
-9 + -3a + (4a + 8) = 0

Reorder the terms:
-9 + -3a + (8 + 4a) = 0

Remove parenthesis around (8 + 4a)
-9 + -3a + 8 + 4a = 0

Reorder the terms:
-9 + 8 + -3a + 4a = 0

Combine like terms: -9 + 8 = -1
-1 + -3a + 4a = 0

Combine like terms: -3a + 4a = 1a
-1 + 1a = 0

Solving
-1 + 1a = 0

Solving for variable 'a'.

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