The equation of the line is given by :
y-y1 = m(x-x1) such that (x1,y1) is any point on the line and m is the slope.
We are given that the point (4,4.5) passes through the line, and the slope m= 0.75
==> y- 4-5 = 0.75 (x-4)
==> y- 4.5 = 0.75x - 3
Now add 4.5
==> y= (0.75)x - 3 + 4.5
==> y= (0.75) x + 1.5
We want the equation of the line that has the slope of .75 and that passes through the point (4, 4.50)
Given a point and its slope, its best to use the point slope form which in general terms is
y - y1 = m(x - x1) where (x1,y1) is the point and m is the slope.
Plug in to this formula.
y - 4.5 = .75(x - 4)