Question 1039433
<pre><b>
The only points with integer coordinates that will 
fit on your graph are these 5

 x | y = 3x+1
----------------------------
-1 | y = 3(-1)+1 = -3+1 = -2
 0 | y = 3(0)+1 = 0+1 = 1
 1 | y = 3(1)+1 = 3+1 = 4
 2 | y = 3(2)+1 = 6+1 = 7
 3 | y = 3(3)+1 = 9+1 = 10

So we plot (-1,-2), (0,1), (1,4), (2,7), (3,10)
and draw a line through them.

{{{drawing(5700/17,400,-5.2,6.2,-3.2,10.4, grid(1),
line(-9,-26,7,22),
circle(-1,-2,0.15),circle(-1,-2,0.13),circle(-1,-2,0.11),circle(-1,-2,0.09),circle(-1,-2,0.07),circle(-1,-2,0.05),circle(-1,-2,0.03),circle(-1,-2,0.01),

circle(0,1,0.15),circle(0,1,0.13),circle(0,1,0.11),circle(0,1,0.09),circle(0,1,0.07),circle(0,1,0.05),circle(0,1,0.03),circle(0,1,0.01),

circle(1,4,0.15),circle(1,4,0.13),circle(1,4,0.11),circle(1,4,0.09),circle(1,4,0.07),circle(1,4,0.05),circle(1,4,0.03),circle(1,4,0.01),

circle(2,7,0.15),circle(2,7,0.13),circle(2,7,0.11),circle(2,7,0.09),circle(2,7,0.07),circle(2,7,0.05),circle(2,7,0.03),circle(2,7,0.01),

circle(3,10,0.15),circle(3,10,0.13),circle(3,10,0.11),circle(3,10,0.09),circle(3,10,0.07),circle(3,10,0.05),circle(3,10,0.03),circle(3,10,0.01)
 )}}}

Edwin</pre></b>