Step-by-step explanation:
Let the coordinates of point b be (x,y).
Given the coordinates of a (-7,5) and c(5,-1)
Now according to question
ab = 5bc
using distance formula
[tex]\sqrt{(x+7)^2+(y-5)^2} =5\sqrt{(5-x)^2+(-1-y)^2}[/tex]
Solving we can get
[tex]x=-\frac{-11+\sqrt{-4y^2-10y+25}}{2},\:x=\frac{\sqrt{-4y^2-10y+25}+11}{2}[/tex]'
However, we do need either x or y coordinate of point b to find the other.