Toán Chứng minh rằng : M = 3^5 + 3^6 + 3^7 + 3^8 + 3^9 + 3^10 chia hết cho 91 11/10/2021 By Faith Chứng minh rằng : M = 3^5 + 3^6 + 3^7 + 3^8 + 3^9 + 3^10 chia hết cho 91
Đáp án: M = 3^5 + 3^6 + 3^7 + 3^8 + 3^9 + 3^10 M=3^5.1+3^5.3+3^5.3^2+3^5.3^3+3^5.3^4+3^5.3^5 M=3^5.(1+3+3^2+3^3+3^4+3^5) M=3^5.(1+3+9+27+81+243) M=3^5.364 M=3^5.4.91 chia hết cho 91 Vậy M chia hết cho 91 CHO MÌNH XIN HAY NHẤT NHA THANK YOU VERY MUCH Trả lời
`M=3^{5}+ 3^{6}+3^{7}+3^{8}+3^{9}+3^{10}``=(3^{5}+3^{7}+3^{9})+(3^{6}+3^{8}+3^{10})``=3^{5}(1+3^{2}+3^{4})+3^{6}(1+5^{2}+3^{4})``=3^{5}.91+3^{6}.91``=91.(3^{5}+3^{6})⋮91` Trả lời
Đáp án:
M = 3^5 + 3^6 + 3^7 + 3^8 + 3^9 + 3^10
M=3^5.1+3^5.3+3^5.3^2+3^5.3^3+3^5.3^4+3^5.3^5
M=3^5.(1+3+3^2+3^3+3^4+3^5)
M=3^5.(1+3+9+27+81+243)
M=3^5.364
M=3^5.4.91 chia hết cho 91
Vậy M chia hết cho 91
CHO MÌNH XIN HAY NHẤT NHA
THANK YOU VERY MUCH
`M=3^{5}+ 3^{6}+3^{7}+3^{8}+3^{9}+3^{10}`
`=(3^{5}+3^{7}+3^{9})+(3^{6}+3^{8}+3^{10})`
`=3^{5}(1+3^{2}+3^{4})+3^{6}(1+5^{2}+3^{4})`
`=3^{5}.91+3^{6}.91`
`=91.(3^{5}+3^{6})⋮91`