## Elementary Geometry for College Students (7th Edition)

$(b, \frac{ab-b^2}{c})$
We first describe the slope. Using the knowledge of the point we are looking for, we see that the equation of the line is: $y=\frac{a-b}{c}x$ We find the slope of one of the lines is: c/b Since this is perpendicular to the other line being considered, we find that the slope of that line is: -b/c (a,0) is on this line, which means the equation of the line can be described as: $y=-b/c(x-a)$ We equate these two equations to have: $\frac{a-b}{c}x=-b/c(x-a)$ Upon solving, we find: x =b We substitute back into the equation to find y: $y = \frac{ab-b^2}{c}$ This gives the point: $(b, \frac{ab-b^2}{c})$