solve for y; 2x+2y=8?

Do as follows:

2x + 2y = 8

Notice that you have a common factor of 2, therefore divide everything by 2

2x/2 + 2y/2 = 8/2

Which then becomes:

x + y = 4

Now substract x from both sides to isolate the y:

x + y - x = 4 - x
x - x + y = 4 - x; collecting like terms
0 + y = 4 - x
y = 4 - x

REMEMBER: That when you are trying to remove a term from one side do the opposite on BOTH sides. Here I eliminated the x by substracting x on both sides.

Hope this helps!

2x + 2y = 8
2y = 8 - 2x
y = 4 - x

Answer: y = 4 - x

Check equality of equation:
2x + 2(4 - x) = 8
2x + 8 - 2x = 8
8 = 8

put x on the other side of the equal sign
2y = -2x + 8
divide both sides by 2 to get y alone
y = -x + 4

2x+2y=8
2y=8-2x
y=(8-2x)/2
y=4-x
You need a value for x to finish solving

2x+2y=8
y=4-x

x=1.5, y=2.5

2x + 2y = 8
2y = 8 - 2x
y = (8 - 2x)/2
y = 4 - x

x + y = 4
y = 4 - x

To solve for y, you need to get it by itself on one side of the equals sign. You can't find a specific number value for it when you have 2 variables (x and y) in one equation.

2x + 2y = 8
2y = 8 - 2x

Divide both sides by 2 to get:
y = 4 - x