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
<span>Take (2,4). y=mx+b or 4=3*2+b, solving for b: b=4-(3)(2). b=-2.</span>
So your final equation is...
<span>y = 3x-2</span>