Đáp án:
co
Giải thích các bước giải:
3^2+3^3+3^4+3^5+…+3^13+3^14+3^15
= (3^2+3^3) + (3^4+3^5) +…+ (3^14+3^15)
= (3^2+3^3) + 3^2.(3^2+3^3) +…+ 3^12.(3^2+3^3)
= 36 + 3^2 . 36 +…+ 3^12 . 36
= 36 . (3^2 +…+3^12)
TAO CO : 36 chia het cho 13 nen
3^2+3^3+3^4+3^5+…+3^13+3^14+3^15 chua het chi 13
may mik ko go tieng dc mong ban thong cam