[size=150]Recall that we already know that in the equation [math]y=mx+b[/math] the [i]m[/i] number represents the pattern of change. The constant add or subtract amount for how the output, the y-value, is changing.[br]This number is called the [size=150][size=200]slope[/size][/size], because graphically is represented in the steepness of the line.[br][br]Lets look at a pattern like the ones we've already seen before. Consider the situation where Bill is filling up a tank of water. The tank started with 8 gallons and he is adding a half gallon of water every minute. The equation that models this is [math]y=\frac{1}{2}x+8[/math][/size][br]