Bài 2: 

a: \(\Leftrightarrow\left(x-5\right)\left(x+5\right)-\left(x+5\right)=0\)

=>(x+5)(x-6)=0

=>x=-5 hoặc x=6

b: \(\Leftrightarrow4x^2-4x+1-4x^2+1=0\)

=>-4x+2=0

hay x=1/2

c: \(\Leftrightarrow\left(x^2+4\right)\left(x^2-1\right)=0\)

=>x=1 hoặc x=-1

8 mũ 300=(8 mũ 3)mũ 100=512 mũ 100

9 mũ 200=(9 mũ 2) mũ 100=81 mũ 100

vì 512 mũ 100< 81 mũ 100 =>8 mũ 300 > 9 mũ 200

chắc chắn 100 %

Ta có :

\(8^{300}=\left(8^3\right)^{100}=512^{100}\)

\(9^{200}=\left(9^2\right)^{100}=91^{100}\)

Vì \(512^{100}>91^{100}\Rightarrow8^{300}>9^{200}\)

\(\left(9^{30}-27^{19}\right):3^{57}+\left(125^9-25^{12}\right):5^{24}\)

\(=\left(3^{60}-3^{57}\right):3^{57}+\left(5^{27}-5^{24}\right):5^{24}\)

\(=3^{57}\left(3^3-1\right):3^{57}+5^{24}\left(5^3-1\right):5^{24}\)

\(=3^3-1+5^3-1\)

\(=27-1+125-1\)

\(=150\)

2 )

\(x^2-25-\left(x+5\right)=0\)

\(\Leftrightarrow\left(x+5\right)\left(x-5\right)-\left(x+5\right)=0\)

\(\Leftrightarrow\left(x+5\right)\left(x-5-1\right)=0\)

\(\Leftrightarrow\left(x+5\right)\left(x-6\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x+5=0\\x-6=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-5\\x=6\end{matrix}\right.\)

Vậy ...

b )

\(\left(2x-1\right)^2-\left(4x^2-1\right)=0\)

\(\Leftrightarrow4x^2-4x+1-4x^2+1=0\)

\(\Leftrightarrow2-4x=0\)

\(\Leftrightarrow4x=2\)

\(\Leftrightarrow x=\dfrac{1}{2}\)

Vậy ...

c )

\(x^2\left(x^2+4\right)-x^2-4=0\)

\(\Leftrightarrow x^2\left(x^2+4\right)-\left(4+x^2\right)=0\)

\(\Leftrightarrow\left(x^2-1\right)\left(x^2+4\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x^2-1=0\\x^2+4=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x^2=1\\x^2=-4\left(L\right)\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=1\\x=-1\end{matrix}\right.\)

Vậy ...

a. \(625^5=\left(5^4\right)^5=5^{20}< 5^{21}=\left(5^3\right)^7=125^7\)

b. với n khác 0 \(3^{2n}=9^n>8^n=2^{3n}\)

Còn với n=0 thì \(3^{2n}=2^{3n}=1\)

Bài làm :

\(\frac{125^6.3^{61}.8^{10}}{4^{15}.25^9.9^{30}}\)

\(=\frac{\left(5^3\right)^6.3^{61}.\left(2^3\right)^{10}}{\left(2^2\right)^{15}.\left(5^2\right)^9.\left(3^2\right)^{30}}\)

\(=\frac{5^{18}.3^{61}.2^{30}}{2^{30}.5^{18}.3^{60}}\)

\(=3\)

Học tốt nhé

        Bài làm :

Ta có :

\(\frac{125^6.3^{61}.8^{10}}{4^{15}.25^9.9^{30}}\)

\(=\frac{\left(5^3\right)^6.3^{61}.\left(2^3\right)^{10}}{\left(2^2\right)^{15}.\left(5^2\right)^9.\left(3^2\right)^{30}}\)

\(=\frac{5^{18}.3^{61}.2^{30}}{2^{30}.5^{18}.3^{60}}\)

\(=\frac{3^{61}}{3^{60}}\)

\(=3\)

`#3107.101107`

a)

`64^150` và `4^450`

Ta có:

`64^150 = (4^3)^150 = 4^(3*150) = 4^450`

Vì `450 = 450 => 4^450 = 4^450 => 64^150 = 4^450`

Vậy, `64^150 = 4^450`

b)

`81^64` và `27^100`

Ta có:

`81^64 = (3^4)^64 = 3^(4*64) = 3^256`

`27^100 = (3^3)^100 = 3^(3*100) = 3^300`

Vì `256 < 300 => 3^256 < 3^300 => 81^64 < 27^100`

Vậy, `81^64 < 27^100`

c)

`125^1000` và `25^3000`

Ta có:

`125^1000 = (5^3)^1000 = 5^(3*1000) = 5^3000`

Vì `5 < 25 => 5^3000 < 25^3000 => 125^1000 < 25^3000`

Vậy, `125^1000 < 25^3000`

d)

`4^30` và `3^40`

Ta có:

`4^30 = 4^(3*10) = (4^3)^10 = 64^10`

`3^40 = 3^(4*10) = (3^4)^10 = 81^10`

Vì `64 < 81 => 64^10 < 81^10 => 4^30 < 3^40`

Vậy, `4^30 < 3^40`

m)

`2^5000` và `5^2000`

Ta có:

`2^5000 = 2^(5*1000) = (2^5)^1000 = 32^1000`

`5^2000 = 5^(2*1000) = (5^2)^1000 = 25^1000`

Vì `32 > 25 => 32^1000 > 25^1000 => 2^5000 > 5^2000`

Vậy, `2^5000 > 5^2000`

h)

`6^450` và `3^750`

Ta có:

`6^450 = 6^(150*3) = (6^3)^150 = 216^150`

`3^750 = 3^(150*5) = (3^5)^150 = 243^150`

Vì `216 < 243 => 216^150 < 243^150 => 6^450 < 3^750`

Vậy, `6^450 < 3^750`

0)

`333^444` và `444^333`

Ta có:

`333^444 = 333^(4*111) = (333^4)^111 = (3^4 *111^4)^111 = 81^111 * 111^444`

`444^333 = 444^(3*111) = (444^3)^111 = (4^3 * 111^3)^111 = 64^111 * 111^333`

Vì `81 > 64;` `111^444 > 111^333`

`=> 81^111 * 111^444 > 64^111 * 111^333`

Vậy, `333^444 > 444^333.`

a) Ta có:

\(64^{150}=\left(2^6\right)^{150}=2^{900}\)

\(4^{450}=\left(2^2\right)^{450}=2^{900}\)

Mà: \(2^{900}=2^{900}\Rightarrow64^{150}=4^{450}\)

b) Ta có:

\(81^{64}=\left(3^4\right)^{64}=3^{256}\)

\(27^{100}=\left(3^3\right)^{100}=3^{300}\)

Mà: \(3^{300}>3^{256}\Rightarrow27^{100}>81^{64}\)

c) Ta có: 

\(125^{1000}=\left(5^3\right)^{1000}=5^{3000}\)

Mà: \(25^{3000}>5^{3000}\Rightarrow25^{3000}>125^{1000}\)

d) Ta có:

\(4^{30}=\left(4^3\right)^{10}=64^{10}\)

\(3^{40}=\left(3^4\right)^{10}=81^{10}\)

Mà: \(81^{10}>64^{10}\Rightarrow3^{40}>4^{30}\)

m) Ta có:

\(2^{5000}=\left(2^5\right)^{1000}=32^{1000}\)

\(5^{2000}=\left(5^2\right)^{1000}=25^{1000}\)

Mà: \(25^{1000}< 32^{1000}\Rightarrow2^{5000}>5^{2000}\)

h) Ta có:

\(6^{450}=\left(6^3\right)^{150}=216^{150}\)

\(3^{750}=\left(3^5\right)^{150}=243^{150}\)

Mà: \(243^{150}>216^{150}\Rightarrow3^{750}>6^{450}\)

.... 

\(25\ge5^x\ge125\)

\(5^2\ge5^x\ge5^3\)

\(2\ge x\ge3\)

x = 3 hoặc x = 2

a) \(9^{21}.9^{33}=9^{21+33}=9^{54}\)

b) \(19^{11}.19.19=19^{11+1+1}=19^{13}\)

c) \(25^2.5^2.125=5^4.5^2.5^3=5^{4+2+3}=5^9\)

d) \(t^{2021}.t^2.\left(t^2\right)^2=t^{2021}.t^2.t^4=t^{2021+2+4}=t^{2027}\)

e) \(123^{14}:123^{13}=123^{14-13}=123\)

f) \(64^2:8^3=\left(8^2\right)^2:8^3=8^4:8^3=8^{4-3}=8=2^3\)

g) \(6^{10}:6^3:36=6^{10}:6^3:6^2=6^{10-3-2}=6^5\)

h) \(m^{20}:m^{10}.m^{10}=m^{20-10+10}=m^{20}\)

oke