a)    \(8^{10}-8^9-8^8\)

\(=8^8.\left(8^2-8-1\right)\)

\(=8^8.55\)\(⋮\)\(55\)

giup de minh cho 

a)\(\left(10^2+11^2+12^2\right)\div\left(13^2+14^2\right)\)

\(=\left(100+121+144\right)\div\left(169+196\right)\)

\(=365\div365\)

\(=1\)

b) \(1.2.3...9-1.2.3...8-1.2.3...8^2\)

\(=1.2.3...8\left(9-1-8\right)\)

\(=1.2.3...8.0\)

\(=0\)

d) \(1152-\left(374+1152\right)+\left(-65+374\right)\)

\(=1152-374-1152-65+374\)

\(=\left(1152-1152\right)-65+\left(374-374\right)\)

\(=0-65+0\)

\(=-65\)

e) \(13-12+11+10-9+8-7-6+5-4+3+2-1\)

\(=13-\left(12-11\right)+\left(10-9\right)+\left(8-7\right)-\left(6-5\right)-\left(4-3\right)\)\(+\left(2-1\right)\)

\(=13-1+1+1-1-1+1\)

\(=13+0+0+0\)

\(=13\)

Câu 6c:

13^40 và 2^161

2^161 = (2^4)^40.2 = 2.(16^40) > 13^40

Vậy 13^40 < 2^161

Câu 6d:

5^300 và 3^453

5^300 = (5^2)^150 = 25^150

3^453 > 3^450 = (3^3)^150 = 27^150

25^150 < 27^150

Vậy 5^300 < 3^453

Đề là gì vậy?

tìm chữ số tận cùng

\(a;5^{23}=5\cdot5^{22}< 6\cdot5^{22}\Rightarrow5^{23}< 6\cdot5^{22}\)

\(b;7\cdot2^{13}< 8\cdot2^{13}=2^3\cdot2^{13}=2^{15}\)

\(c;21^{15}=3^{15}\cdot7^{15}>3^{15}\cdot7^{14}=27^5\cdot49^8\)

\(d;199^{20}< 200^{20}=10^{40}\cdot2^{20}< 10^{45}\cdot2^{15}=2000^{15}< 2001^{15}\)

\(e;3^{39}=9^{13}< 11^{13}< 11^{21}\)

\(b)\)\(9!-8!-7!.8^2\)

\(=\)\(8!\left(9-1\right)-7!.8^2\)

\(=\)\(7!.8.8-7!.8^2\)

\(=\)\(7!.8^2-7!.8^2\)

\(=\)\(0\)

\(c)\)\(\frac{\left(3.4.2^{16}\right)^2}{11.2^{13}.4^{11}-16^9}\)

\(=\)\(\frac{\left(2^2\right)^2.\left(2^{16}\right)^2.3^2}{2^{13}.\left(2^2\right)^{11}.11-\left(2^4\right)^9}\)

\(=\)\(\frac{2^4.2^{32}.3^2}{2^{13}.2^{22}.11-2^{36}}\)

\(=\)\(\frac{2^{36}.3^2}{2^{35}.11-2^{36}}\)

\(=\)\(\frac{2^{36}.3^2}{2^{35}\left(11-2\right)}\)

\(=\)\(\frac{2.3^2}{9}\)

\(=\)\(\frac{2.3^2}{3^2}\)

\(=\)\(2\)