What is an approximate equation passing through the lines (2,4) and (3,7)

First, let's find what m is, the slope of the line ...

m = y2-y1/x2-x1

m=7-4/3-2 You end up with 3/1 or 3 as your slope.

so far you have ... y=3x+b

Take (2,4). y=mx+b or 4=3*2+b, solving for b: b=4 - (3) (2). b=-2.

So your final equation is ...

y = 3x-2