15x \equiv 20 (mod 88)
13=88-5*15
2=15-1*13
1=13-2*6
GCF is 1.
Im trying to use backwards substitution and so far have
1=13-2*(15-1*13)
but I dont understand what to do next, can anyone help?
Maybe this can help you:
https://www.youtube.com/watch?v=fz1vxq5ts5I