Answer:
y=mx+b
m = slope
b = y-intercept
To find slope we use the equation, change in y divided by the change in x. Let's use points (2, 2) and (3, 1).
(2-1) / (2-3) = -1
Meaning our slope is -1 and it will be going down.
Next, we have to find the y-intercept which is the value of y when x=0. When x is 0 y will be 4.
y=-1x+4
