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

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

Simplifying
3a + -9b + -1(4a + -8b) = 0
3a + -9b + (4a * -1 + -8b * -1) = 0
3a + -9b + (-4a + 8b) = 0

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

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

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

Solving
-1a + -1b = 0

Solving for variable 'a'.

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

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

Combine like terms: -1b + b = 0
-1a + 0 = 0 + b
-1a = 0 + b
Remove the zero:
-1a = b

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

Simplifying
a = -1b