I know that the simple equation for a linear graph with a slope of one is:

y=x

If my x intercept is -1 and my y intercept is 1 how would I express this in an equation? I've tried looking in places like Math professor but I don't know what year of learning this trinket of knowledge comes from.

Is there anyone who could help me find a page explaining this, or some examples of changing a graph into an expression?

Any help would be greatly appreciated.

~Edit~

To clarify:

I understand the concept of it, I only need help expressing the actual thing. I can't figure out where the numbers go.

y=x is the equation.

x=-1

y=1

but the equation wouldn't be -1=1

would it be y=-x?