Question

Find a,b and c if
n^2-n=a(n-4)^2+b(n-4)+c

Answer 1

Hints:
Expand left side: n^2-n=0
Expand right side: an^2+(b-8a)n+(c-4b+16a)
Compare coefficients of each power, so
a=1, (b-8a)=-1, (c-4b+16a)=0
Solve for a, b and c.