How do you graph an equation in two variables?

(x,y)
there are 2 easy ways, number 2 works better with y=mx+b form equations
1. subsitute and graph points
2. find y-intercept and slope

1. subsitute
lets say you have the equation
y=3x+4
if x=3 then y= subsitute 9+4=13
so one point is (3,13)
subsitte 0 for x
if x=0 then y=4
(0,4) is another point,
plot the line with points (3,13) and (0,4)

2.
find y intercept
in y=mx+b form, b= y intercept or where the line crossses the y axis
so if you had y=3x+4 the line would cross the y axis at (0,4)
and if you had y=3x-4 it would cross at (0,-4)
m=slope
rise divided by run or (how far it goes up)/(how far it goes to the right)
slope=3/1