2x + y = 9 for y
2x + y = 9 for y
What you want to do is to move what you solve for (in this case y) to one side and everything else to the other side.
Subtract 2x from both sides, then combine terms.
2x - 2x + y =9 - 2x
y = 9-2x
What you want to do is to move what you solve for (in this case y) to one side and everything else to the other side.
Subtract 2x from both sides, then combine terms.
2x - 2x + y =9 - 2x
y = 9-2x