Chứng tỏ rằng: a, 7 mũ 8 cộng 7 mũ 9 cộng 7 mũ 10 chia hết cho 57
Giải thích
a, 78+79+710=78.1+7+72 = 78.57⋮57
b, 1010-109-108 = 108.(102-10-1) = 108.89⋮89
c, 6410-3211-163 = (26)10-(25)11-(24)13 = 260-255-252=25228-23-1
= 252.247=252.13.19⋮19
a, 78+79+710=78.1+7+72 = 78.57⋮57
b, 1010-109-108 = 108.(102-10-1) = 108.89⋮89
c, 6410-3211-163 = (26)10-(25)11-(24)13 = 260-255-252=25228-23-1
= 252.247=252.13.19⋮19