Calculus 10th Edition

Point one: $(1+1,7-3\times1)=(2,4)$. Point two: $(1+2,7-3\times2)=(3,1)$. Point three: $(1+3,7-3\times3)=(4,-2)$.
We will use the property that if $x$ increases by $\Delta x$ then $y$ increases by $m\Delta x$ where $m$ is the slope so if the graph contains a point $(6,2)$, then it also contains $(1+\Delta x, 7+m\Delta x)$. Since we need three points we can use $\Delta x=1,2,3$: Point one: $(1+1,7-3\times1)=(2,4)$. Point two: $(1+2,7-3\times2)=(3,1)$. Point three: $(1+3,7-3\times3)=(4,-2)$.