Y=3x-1
Without further information I can only guess that this question needs to be put in slope-intercept form and said equation must pass through the point (1,2).
The slope-intercept equation is very simply: y=mx+b. In this case we are given all the variables but b, so we are are solving for b (our y-intercept).
We are first given our slope (or m) of the equation which is 3. From the given point we are given the x and y with 1 being our x and 2 being our y. So with all these numbers we can plug them in to get the equation 2=3(1)+b.
With the equation 2=3(1)+b we need to solve for b. So the new equation is 2=3+b. To find b we need to isolate it in the equation so subtract 3 on each side which will leave you with -1=b or b=-1. Now that we know that he is -1 we can add it to the equation which will now look like 2=3-1 or in slope intercept form y=3x-1
