CMR:
a, 8\(^7\)-2\(^{18}\)⋮14
b, 10\(^6\)-5\(^7\)⋮59
CMR:
a/\(8^7-2^{18}\)chia hết cho 14
b/\(10^6-5^7\) chia hết cho 59
a) \(8^7-2^{18}=\left(2^3\right)^7-2^{18}=2^{21}-2^{18}=2^{17}\left(2^4-2\right)=2^{17}.\left(16-2\right)=2^{17}.14⋮14\)
b) \(10^6-5^7=5^6.2^6-5^7=5^6.\left(2^6-5\right)=5^6.\left(64-5\right)=5^6.59⋮59\)
a, 8^7 - 2^18 chia hết 14
b, 10^6 - 5^7 chia hết 59
c, 12^8 . 9^12 = 18^16
d, 75^20 = 45^10 . 5^30
a, 8^7 - 2^18 chia hết 14
b, 10^6 - 5^7 chia hết 59
c, 12^8 . 9^12 = 18^16
d, 75^20 = 45^10 . 5^30
a, 8^7 - 2^18 chia hết 14
b, 10^6 - 5^7 chia hết 59
c, 12^8 . 9^12 = 18^16
d, 75^20 = 45^10 . 5^30
Chung minh rang:
a/ 36^20-9^10 : 405
b/ 8^12-2^33-2^30 : 55
c/ 8^7-2^18 :14
d/ 10^6-5^7 ;59
b: \(8^{12}-2^{33}-2^{30}\)
\(=2^{36}-2^{33}-2^{30}\)
\(=2^{30}\left(2^6-2^3-1\right)=2^{30}\cdot55⋮55\)
c: \(8^7-2^{18}=2^{21}-2^{18}\)
\(=2^{18}\left(2^3-1\right)=2^{17}\cdot14⋮14\)
d: \(10^6-5^7\)
\(=2^6\cdot5^6-5^7\)
\(=5^6\left(2^6-5\right)=5^6\cdot59⋮59\)
CMR:
a)8^7-2^18 chia hết cho 14
b)10^6-5^7 chia hết cho 59
c)313^5*299-313^6*35 chia hết cho 7
d)3^n+2-2^n+2+3^n-2^n chia hết cho 10
e)3^n+3+2^n+3+3^n+1+2^n+2 chia hết cho 6
f)7^6+7^5-7^4 chia hết cho 11
Bài 7: chứng minh rằng
a) \(8^7-2^{18}⋮14\)\(^{ }\)
b) \(10^6-5^7⋮\)59
a, Ta có :
\(8^7-2^{18}\)
\(=\left(2^3\right)^7-2^{18}\)
\(=2^{21}-2^{18}\)
\(=2^{18}\left(2^3-1\right)\)
\(=2^{18}.7\)
\(=2^{17}.2.7\)
\(=2^{17}.14⋮14\)
\(\Leftrightarrow8^7-2^{18}⋮14\rightarrowđpcm\)
b, \(10^6-5^7\)
\(=\left(2.5\right)^6-5^7\)
\(=2^6.5^6-5^7\)
\(=2^6.5^6-5^6.5\)
\(=5^6\left(2^6-5\right)\)
\(=5^6.59⋮59\)
\(\Leftrightarrow10^6-5^7⋮59\rightarrowđpcm\)
\(8^7-2^{18}\)
\(=\left(2^3\right)^7-2^{18}\)
\(=2^{21}-2^{18}\)
\(=2^{18}.2^3-2^{18}.1\)
\(=2^{18}.\left(2^3-1\right)\)
\(=2^{18}.7\)
\(=2^{17}.14⋮14\rightarrowđpcm\)
\(10^6-5^7\)
\(=\left(2.5\right)^6-5^7\)
\(=2^6.5^6-5^7\)
\(=64.5^6-5^6.5\)
\(=5^6\left(64-5\right)\)
\(=5^6.59⋮59\rightarrowđpcm\)
CM : 8 mũ 7 - 2 mũ 18 chia hết cho 14
10 mũ 6 - 5 mũ 7 chia hết cho 59
Chứng minh rằng :
a) \(8^7-2^{18}⋮14\)
b) \(10^6-5^7⋮59\)
a) \(8^7-2^{18}=\left(2^3\right)^7-2^{18}=2^{21}-2^{18}\)
\(=2^{17}\left(2^4-2\right)=2^{17}.\left(16-2\right)=2^{17}.14⋮14\)
Bổ sung phần b)
\(10^6-5^7=2^6.5^6-5^6.5=5^6\left(2^6-5\right)=5^6\left(64-5\right)=5^6.59⋮59\)