2x + 4 = 9 - y

y= -2x-13

x= 5.5 -1/2y

2x + 4 = 9 - y,

y + 2x + 4 = 9,
y + 2x = 9 - 4,
y + 2x = 5,
y = 5 - 2x.

2x + 4 = 9 - y,
2x = 9 - y - 4,
2x = 5 - y,
x = 5/2 - y/2.

To solve the equation 2x + 4 = 9 - y, we need to isolate the variable on one side of the equation.

Step 1: Move all the variable terms to the same side of the equation by adding y to both sides:
2x + y + 4 = 9

Step 2: Move the constant term to the other side by subtracting 4 from both sides:
2x + y = 9 - 4
2x + y = 5

Now the equation is in the form "variable = constant" or "constant = variable".