This is the question I am having trouble with:

Find the equation of the line joining each pair of given points- (-1,4) and (0,7).

This is my working:

Find the midpoint which is (1.5,3.5) then find the gradient which is 3. then write the equation y-3.5=3(x-1.5) then expand and rearange to form the equation 3x-y-1=0.

My answer is correct except for the -1 part. Could someone please show mw what I did wrong?