Bài 8:

a) \(2^{225}=\left(2^3\right)^{75}=8^{75}\)

\(3^{150}=\left(3^2\right)^{75}=9^{75}\)

Vì \(8^{75}< 9^{75}\Rightarrow2^{225}< 3^{150}\)

b) \(2^{91}=\left(2^{13}\right)^7=8192^7\)

\(5^{35}=\left(5^5\right)^7=3125^7\)

Vì \(8192^7>3125^7\Rightarrow2^{91}>5^{35}\)

c) \(99^{20}=\left(99^2\right)^{10}=9801^{10}< 9999^{10}\)

7520 = 4510.530

Ta có: 4510.530 = (9.5)10.530 = 910.510.530 = (32)10.540

=320.(52)20 = 320.2520 = (3.25)20 = 7520

Vế phải bằng vế trái nên đẳng thức được chứng minh

27549 + 7520 = 35069

k mk mk k lại

de khong phai la : 27549+7520+=dau ma phai la : 27549+7520=moi dung em viet thuc dau cong roi 

27549+7520=35069

chuc em thanh cong trong hoc tap 

good luck to you !

Tổng 2 số là 27549+7520=35069

                      ĐS 35069

C

C

C

TL

\(\frac{7520}{6400} > \frac{70}{196}

nha bn

HT

7520/6400>70/196

7520/6400 lớn hơn nhé

Đáp án C

45 10   = 4,5

543 100   =   5,43

96 100   = 0,96

4331 1000  = 4,331

ƯCLN(530;410)=10

ƯCLN(410;205)=5

ƯCLN(205;150)=5

ƯC(410;150)={1;2;5;10}

ƯCLN(530;205;150)=5

\(70-5\cdot\left(x-3\right)=45\)

\(\Rightarrow5\cdot\left(x-3\right)=70-45\)

\(\Rightarrow5\cdot\left(x-3\right)=25\)

\(\Rightarrow x-3=\dfrac{25}{5}\)

\(\Rightarrow x-3=5\)

\(\Rightarrow x=5+3=8\)

==============

\(10+2\cdot x=4^5:4^3\)

\(\Rightarrow10+2\cdot x=4^2\)

\(\Rightarrow10+2\cdot x=16\)

\(\Rightarrow2\cdot x=16-10\)

\(\Rightarrow2\cdot x=6\)

\(\Rightarrow x=\dfrac{6}{2}=3\)

=============

\(2\cdot x-138=2^3\cdot3^2\)

\(\Rightarrow2\cdot x-138=72\)

\(\Rightarrow2\cdot x=72+138\)

\(\Rightarrow2\cdot x=210\)

\(\Rightarrow x=\dfrac{210}{2}=105\)

==============

\(231-\left(x-6\right)=1339:12\)

\(\Rightarrow231-x+6=1339:12\)

\(\Rightarrow237-x=\dfrac{1339}{12}\)

\(\Rightarrow x=237-\dfrac{1339}{12}\)

\(\Rightarrow x=\dfrac{1505}{12}\)