Skip to content / Đến nội dung
ThichHocToan.com

HKIMO 2019 Grade 9 National Final (Heat) Set 02 Question 15

HKIMO · HKIMO 2019 Grade 9 National Final (Heat) Set 02

Question 15

If $k^2+(n-223)k-899=0$ and $n=1+3+5+7+\cdots+k$, find nk.