Answer:

Explanation:
The point-slope form of a line is given by:

Where
(x_1,y_1) is the coordinate pair (any of the points given)
m is the slope. The ratio of change in y coordinates by x coordinates
Let's calculate the slope:

Now, it is given "y - 4", so y_1 is 4, so they are using the coordinate pair (7,4). So we can say x_1 = 7
Now we have all the values, lets write the equation:

This is the point-slope form.