Determining Rate of Change and Y-Intercept from Data Tables and Graphs(TEKS.Math.8.4.C)

Compute slope with any two points, say $(1,2)$ and $(3,8)$: $m=\frac{8-2}{3-1}=\frac{6}{2}=3$. Use $b=y-mx$ with $(1,2)$: $b=2-3(1)=-1$. So $(m,b)=(3,-1)$.