4-(-9)=y

Solution for 4-(-9)=y equation:

Simplifying
4 + -1(-9) = y

Multiply -1 * -9
4 + 9 = y

Combine like terms: 4 + 9 = 13
13 = y

Solving
13 = y

Solving for variable 'y'.

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

Add '-1y' to each side of the equation.
13 + -1y = y + -1y

Combine like terms: y + -1y = 0
13 + -1y = 0

Add '-13' to each side of the equation.
13 + -13 + -1y = 0 + -13

Combine like terms: 13 + -13 = 0
0 + -1y = 0 + -13
-1y = 0 + -13

Combine like terms: 0 + -13 = -13
-1y = -13

Divide each side by '-1'.
y = 13

Simplifying
y = 13