A group of friends decided to divide the $800 I’ll write the problem as an equation:n=Number of friendsc=Individual cost per friend800/n=c800=(n-2)(c+20)800=(n-2)([800/n]+20)800=800+20n-1600/n-400=20n-1600/n-4020n^2-40n-1600=020(n^2–2n-80)=020(n-10)(n+8)=0n=10 or n=-8So there were 10 friends, let’s verify:800/n=c800/10=80800/(10–2)=c+20800/8=100100=c+20=80+20So yeah, 10 friends Other way 800/(n-2) – 800/n =20Simplifying, n(n-2) = 80if we let n = x+1, this becomes (x+1)(x-1) = x² – 1 =80x² = 81, so x = 9. Originally 10 friends less 2 leaving 8.Price goes from $80/person to $100 per person