cu thach

a/ 27.3^x =243

        3^x =243:27

        3^x=9

        3^x =3²

        x=2

b/ 64.4^x =4⁵

  4³ .4^x=4⁵

      4^x=4⁵:4³

       4^x=4²

       x=2

c/(3^x+5²) =289

(3^x+5²)=17²

3^x+5=17

3^x=17-5

3^x=12

x=12:3=4

d/3^2x+1 .11=2673

3^2x+1         =2673:11

3^2x+1         =243

3^{2x+1      =}3⁵

2x+1=5

2x=5-1

2x=4

x=4:2

x=2

\(2^n=32\)

\(\Leftrightarrow2^n=2^5\)

\(\Rightarrow n=5\)

\(27.3^n=243\)

\(\Leftrightarrow3^n=9\)

\(\Leftrightarrow3^n=3^2\)

\(\Rightarrow n=2\)

\(64.4^n=45\)

câu này ko biết làm ^.^

+/\(2^n=32\)(=) \(2^n=2^5\)

=> \(n=5\)

+/\(64.4^n=4^5\) (=) \(4^3.4^n=4^5\)

(=)\(4^n=4^2\) => \(n=2\)

 Các ý còn lại bạn tự làm nhé !!

2^5 = 32

64*4^2=4^5

27*3^2=243

49*7^2=2401

9<3^3<81

Đây là tìm n nhé bn

`(17+x)-(352-400)=-32`

`17+x-352+400=-32`

`x=-32-17+352-400`

`x=-97`

`-5-(24-2xx x)=-11`

`-5-24+2x=-11`

`2x=-11+5+24`

`2x=18`

`x=9`

\(a,\left(17+x\right)-\left(352-400\right)=-32\)

\(\Rightarrow17+x+48=-32\)

\(\Rightarrow17+x=-80\)

\(\Rightarrow x=-97\)

_____________________________

\(b,-5-\left(24-2x\right)=-11\)

\(\Rightarrow-5-24+2x=-11\)

\(\Rightarrow-29+2x=-11\)

\(\Rightarrow2x=-40\)

\(\Rightarrow x=-20\)

\(a,\left(17+x\right)-\left(352-400\right)=-32\\ \left(17+x\right)-\left(-48\right)=-32\\ 17+x=-32-48\\ 17+x=16\\ x=-80-17\\ x=-97\\ b,-5-\left(24-2.x\right)=-11\\ 24-2.x=-5-\left(-11\right)\\ 24-2.x=6\\ 2.x=24-6\\ 2.x=18\\ x=18:2\\ x=9\)

Bài 3:

a) Ta có: \(2^x\cdot4=128\)

\(\Leftrightarrow2^x=32\)

hay x=5

Vậy: x=5

b) Ta có: \(2^x-26=6\)

\(\Leftrightarrow2^x=32\)

hay x=5

Vậy: x=5

c) Ta có: \(27\cdot3^x=3^7\)

\(\Leftrightarrow3^x=\frac{3^7}{27}=\frac{3^7}{3^3}=3^4\)

hay x=4

Vậy: x=4

d) Ta có: \(3^x=81\)

\(\Leftrightarrow3^x=3^4\)

hay x=4

Vậy: x=4

e) Ta có: \(64\cdot4^x=4^5\)

\(\Leftrightarrow4^3\cdot4^x=4^5\)

\(\Leftrightarrow4^{x+3}=4^5\)

\(\Leftrightarrow x+3=5\)

hay x=2

Vậy: x=2

g) Ta có: \(49\cdot7^x=2401\)

\(\Leftrightarrow7^2\cdot7^x=7^4\)

\(\Leftrightarrow7^{x+2}=7^4\)

\(\Leftrightarrow x+2=4\)

hay x=2

Vậy: x=2

h) Ta có: \(3^4\cdot3^x=3^7\)

\(\Leftrightarrow3^{x+4}=3^7\)

\(\Leftrightarrow x+4=7\)

hay x=3

Vậy: x=3

Trả lời:

H.(7x-11)³ =2⁵.5² +200

=(7x-11)³ =32.25 +200    =(7x-11)³ =800 +200

=(7x-11)³ =1000               =(7x-11)³ = 10³ 

= 7x-11    = 10                  = 7x        = 10 + 11

= 7x         = 21                  =   x         = 21:7

= x           = 3

I.3^x +25   = 26.2²+2.3⁰

=3^x +25   = 26.4 +2.1        =3^x +25     = 106

=3^x            = 106-25          =3^x            = 81

=3^x               = 3⁴                  => x           =4

K.27.3^x= 243

= 3^x      =243:27

= 3^x      = 9

= 3^x      = 3²

=>  x     = 2

Mấy câu khác cứ thế làm nha

Cảm ơn bạn nha

\(a,3x-30=3^5:3^2\\ \Rightarrow3x-30=3^3\\ \Rightarrow3x-30=27\\ \Rightarrow3x=57\\ \Rightarrow x=19\\ b,120-4\left(9+x\right)=16\\ \Rightarrow4\left(9+x\right)=104\\ \Rightarrow9+x=26\\ \Rightarrow x=17\)

x=13

h nha lấy 16^8 : cho 64 ra kq rồi cho mũ 4 lên là dc k mik nha

ban giai gium di

\(64\cdot4^x=16^8\)

\(2^6\cdot2^{2x}=2^{32}\)

\(2^{6+2x}=2^{32}\)

=> 6 + 2x = 32

=> 2x = 26

=> x = 13

a: Ta có: \(4x\left(x-7\right)-4x^2=56\)

\(\Leftrightarrow4x^2-7x-4x^2=56\)

hay x=-8

b: Ta có: \(12x\left(3x-2\right)-\left(4-6x\right)=0\)

\(\Leftrightarrow36x^2-24x-4+6x=0\)

\(\Leftrightarrow36x^2-18x-4=0\)

\(\text{Δ}=\left(-18\right)^2-4\cdot36\cdot\left(-4\right)=900\)

Vì Δ>0 nên phương trình có hai nghiệm phân biệt là:

\(\left\{{}\begin{matrix}x_1=\dfrac{18-30}{72}=\dfrac{-1}{6}\\x_2=\dfrac{18+30}{72}=\dfrac{2}{3}\end{matrix}\right.\)

c: Ta có: \(4\left(x-5\right)-\left(x-5\right)^2=0\)

\(\Leftrightarrow\left(x-5\right)\left(4-x+5\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=5\\x=9\end{matrix}\right.\)