cho S= 2+2^2+2^3+2^4+….+2^95+2^96. Chứng tỏ S chia hết cho 21 Giúp mik vs, mik cần gấp 19/11/2021 Bởi Ariana cho S= 2+2^2+2^3+2^4+….+2^95+2^96. Chứng tỏ S chia hết cho 21 Giúp mik vs, mik cần gấp
S=2+2^2+2^3+2^4+….+2^95+2^96. S=(2+2^2+2^3+2^4+2^5+2^6)+(2^7+2^8+2^9+2^10+2^11)+….+(2^91+2^92+2^93+2^94+2^95+2^96) S=2.63+2^7.63+…+2^91.63 S=(2+2^7+….+2^91).63 chia hết cho 21 ⇒S chia hết cho 21 Bình luận
S=2+2^2+2^3+2^4+….+2^95+2^96.
S=(2+2^2+2^3+2^4+2^5+2^6)+(2^7+2^8+2^9+2^10+2^11)+….+(2^91+2^92+2^93+2^94+2^95+2^96)
S=2.63+2^7.63+…+2^91.63
S=(2+2^7+….+2^91).63 chia hết cho 21
⇒S chia hết cho 21