I think what you mean is that you need to find an equation of the line that passes through the point (4,2) and parallel to the line y= (-3/4)x -5
To find the equation we will use the standard form of the equation in the slope form.
==> y-y1= m (x-x1)
such that (x1,x2) is any point passes through the line and m is the slope.
==> We are given the point (x1,y1)= (4,2)
==> y-2 = m (x-4)
Now we need to find the slope.
Since we know that equation of the parallel line , then we know that the slopes are the same.
==> Then the slope m is -3/4
==> y-2 = (-3/4) (x-4)
Now we will simplify.
==> y-2 = (-3/4)x -(3/4)(-4)
==> y-2 = (-3/4)x + 3
==> y= (-3/4)x + 5