a. \(5^{127}=5.5^{126}=5.125^{72}>119^{72}\)

\(\Rightarrow5^{217}>119^{72}\)

b. \(2^{1000}=\left(2^5\right)^{200}=32^{200}\)

\(5^{400}=\left(5^2\right)^{200}=25^{200}\)

\(\Rightarrow2^{1000}>5^{400}\)

c. \(9^{12}=\left(3^2\right)^{12}=3^{24}\)

\(27^7=\left(3^3\right)^7=3^{21}\)

\(\Rightarrow9^{12}>27^7\)

d. \(125^{80}=\left(5^3\right)^{80}=5^{240}\)

\(25^{118}=\left(5^2\right)^{118}=5^{236}\)

\(\Rightarrow125^{80}>25^{118}\)

e. \(5^{40}=\left(5^4\right)^{10}=625^{10}\)

\(\Rightarrow5^{40}>620^{10}\)

f. \(27^{11}=\left(3^3\right)^{11}=3^{33}\)

\(81^8=\left(3^4\right)^8=3^{32}\)

\(\Rightarrow27^{11}>81^8\)

Bạn có thể ghi cho tiết đề bài và bạn muốn làm gì cho bài đó được không?

a/

\(2^{1050}=\left(2^2\right)^{525}=4^{525}< 5^{525}< 5^{540}\)

b/

\(2^{161}>2^{160}=\left(2^4\right)^{40}=16^{40}>13^{40}\)

c/

\(17^{14}>16^{14}=\left(2^4\right)^{14}=2^{56}>2^{55}=\left(2^5\right)^{11}=32^{11}>31^{11}\)

100 + 320 + 540 + 760 + 980 = 540 + 900 + 360 + 120 + 780

dấu = 

hok tốt ~

100 + 320 + 540 + 760 + 980 = 540 + 900 + 360 + 120 + 780

100+320+540+760+980

=

540+900+360+120+780

100 + 320 + 540 + 760 + 980 = 540 + 900 + 360 + 120 + 780

Sửa đề

Bài 1: So sánh\(5^{40}\)và\(4^{50}\)

a) a>b vi 1234>999

b) x<y vi 8754<87540

Đặt \(A=1+5^2+5^4+...+5^{40}\)

\(\Rightarrow25A=5^2+5^4+5^6+...+5^{42}\)

Lấy \(25A-A=\left(5^2+5^4+5^6+...+5^{42}\right)-\left(1+5^2+5^4+...+5^{40}\right)\)

\(\Rightarrow24A=5^{42}-1\)

\(\Rightarrow A=\dfrac{5^{42}-1}{24}\)

nguyễn thị hương giang, cúm ơn rất nhìu !!