A pool has some initial amount of water in it. Then it starts being filled so the water level rises at a rate of 6 centimeters per minute. After 20 minutes, the water level is 220 centimetersGraph the pool's water level (in centimeters) as a function of time (in minutes).

y = mx + b
slope(m) = 6
(20,220)....x = 20 and y = 220
now sub and find b, the y int
220 = 6(20) + b
220 = 120 + b
220 - 120 = b
100 = b
so ur equation is : y = 6x + 100

to graph :
y = 6x + 100.....u have a slope of 6....u have a y int of 100 or (0,100)...
I would say plot (0,100) and since ur slope is 6, go up 6 and to the right 1...but that is not to helpful because ur graph is not in intervals of 1.
So we will find some points on ur line.

y = 6x + 100....when x = 5
y = 6(5) + 100
y = 30 + 100
y = 130....so another point on ur line is (5,130)

y = 6x + 100...subbing in 10 for x
y = 6(10) + 100
y = 60 + 100
y = 160....another point is (10,160)

keep finding points this way...here are some more...
(15,190) , (20,220), (25,250)