Y=-1 & 3x +y=5 solve the system

Question

luigi0210 · Answer

Plug in -1 and that will give you x

anonymous · Answer

So how would I graph this? @luigi0210

luigi0210 · Answer

Graph both of them?

anonymous · Answer

Yes, my book says to solve the system @luigi0210

luigi0210 · Answer

So solving by graphing, okay. 
So the first one is y=-1, which is just a horizontal line across the y-axis. 
The second, x+y=5, needs to be changed into slope intercept form, can you change it?

anonymous · Answer

I changed it to y=-3x+5

anonymous · Answer

Graph both and the answer is where the two equations intersect.
As a corollary to this, parallel equations have no answers and equations that are the same have infinitely many answers

luigi0210 · Answer

Good, so now that we have the equation in slope-intercept form we can graph them. 
So graph y=-1 for me first