You can use similar triangles
So if AB:BC = 5:3 that means AB:AC = 5:8
The Δx for AC is 24 and the Δy is 12
Using the ratio, we can say that the LSF is 5/8
So Δx for AB must be 15 and the Δy would be 15/2
So adding this onto the coords of A we get that B has coords (11, -2.5)
#Further Gcse
faint matrix
harsh python
cheers