-(-x)+(-y)=0

Solution for -(-x)+(-y)=0 equation:

Simplifying
-1(-1x) + (-1y) = 0

Remove parenthesis around (-1x)
-1 * -1x + (-1y) = 0

Multiply -1 * -1
1x + (-1y) = 0

Solving
1x + (-1y) = 0

Solving for variable 'x'.

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

Add '(y)' to each side of the equation.
1x + (-1y) + (y) = 0 + (y)
1x + (-1y) + y = 0 + (y)

Combine like terms: (-1y) + y = 0
1x + 0 = 0 + (y)
1x = 0 + (y)
1x = 0 + y
Remove the zero:
1x = y

Divide each side by '1'.
x = y

Simplifying
x = y