To write an equation, the first step is to look at the rise/run. In this graph, the rise is 3 and the run is 1. 3 divided by 1 is still 3 so in the equation mx+b, the m, also known as the slope, would be 3.
3x+b
And the b is the y-intercept where the line crosses the y axis.
Joe completes an average of (10 ft)/(5 h) = 2 ft/hour. Bill completes an average of (10 ft)/(4 h) = 2.5 ft/hour. Together, they complete 2+2.5 = 4.5 ft/hour. At that rate, it will take them
