-(a+b)-(x-y)=

Solution for -(a+b)-(x-y)= equation:

Simplifying
-1(a + b) + -1(x + -1y) = 0
(a * -1 + b * -1) + -1(x + -1y) = 0
(-1a + -1b) + -1(x + -1y) = 0
-1a + -1b + (x * -1 + -1y * -1) = 0
-1a + -1b + (-1x + 1y) = 0

Solving
-1a + -1b + -1x + 1y = 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 + -1x + b + 1y = 0 + b

Reorder the terms:
-1a + -1b + b + -1x + 1y = 0 + b

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

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

Combine like terms: -1x + x = 0
-1a + 0 + 1y = b + x
-1a + 1y = b + x

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

Combine like terms: 1y + -1y = 0
-1a + 0 = b + x + -1y
-1a = b + x + -1y

Divide each side by '-1'.
a = -1b + -1x + y

Simplifying
a = -1b + -1x + y