The relationship between Sabir and calories he burns can be modeled using a linear function given by: y=ax+b where a=slope b=y-intercept from the graph, the slope will be given as follows: taking points (3,15) and (12,60) a=(60-15)/(12-3)=5 calories/minute thus using the slope and a point (3,15) the equation will be: a(x1-x)=(y1-y) plugging the values we obtain: 5(x-3)=y-15 5x-15=y-15 thus y=5x thus the equation is: y=5x