Question

y= mx +b
using points (1,2)

Answer 1

You need either another point, or a slope to solve this.

Answer 2

slope is 2/3

Answer 3

So then you will just plug it into the point slope formula:
\[y-k = m(x-h)\]

Where m is your slope, and (h,k) is a point on the line. From there you can get the y=mx+b form if you solve for y.