viết thế này thánh hiểu

3^x + 2 + 4.3 +1 = 7.3^6

3^x + 2 + 12 + 1 = 21^6

3^x + 15 = 21^6

ko làm được nữa thì hịu

\(3^{x+1}+3^{x+2}=324\\ \Rightarrow3^{x+1}\left(1+3\right)=324\\ \Rightarrow3^{x+1}=324:4=81=3^4\\ \Rightarrow x+1=4\Rightarrow x=3\)

\(3^x+4\cdot3^{x-2}=333\)

\(\Rightarrow3^{x-2+2}+4\cdot3^{x-2}=333\)

\(\Rightarrow3^{x-2}\cdot\left(3^2+4\right)=333\)

\(\Rightarrow3^{x+2}\cdot\left(9+4\right)=333\)

\(\Rightarrow3^{x+2}\cdot13=333\)

\(\Rightarrow3^{x+2}=333:13\)

\(\Rightarrow3^{x+2}=\dfrac{333}{13}\)

Không có x nào thỏa mãn

⇒ x ∈ ∅

Mk cần gấp á. Ai hỗ trợ mk với

Bài 1:

a) \(4^{x+2}+4^x=68\)

\(\Rightarrow4^x\cdot\left(4^2+1\right)=68\)

\(\Rightarrow4^x\cdot17=68\)

\(\Rightarrow4^x=\dfrac{68}{17}\)

\(\Rightarrow4^x=4\)

\(\Rightarrow4^x=4^1\)

\(\Rightarrow x=1\)

b) \(5\cdot2^{x+4}-3\cdot2^x=308\)

\(\Rightarrow2^x\cdot\left(5\cdot2^4-3\right)=308\)

\(\Rightarrow2^x\cdot\left(5\cdot16-3\right)=308\)

\(\Rightarrow2^x\cdot77=308\)

\(\Rightarrow2^x=\dfrac{308}{77}\)

\(\Rightarrow2^x=4\)

\(\Rightarrow2^x=2^2\)

\(\Rightarrow x=2\)

c) \(4\cdot3^{x+1}+7\cdot3^x=513\)

\(\Rightarrow3^x\cdot\left(4\cdot3+7\right)=513\)

\(\Rightarrow3^x\cdot19=513\)

\(\Rightarrow3^x=\dfrac{513}{19}\)

\(\Rightarrow3^x=27\)

\(\Rightarrow3^x=3^3\)

\(\Rightarrow x=3\)

d) \(5^{x+4}-5^x=3120\)

\(\Rightarrow5^x\cdot\left(5^4-1\right)=3120\)

\(\Rightarrow5^x\cdot\left(625-1\right)=3120\)

\(\Rightarrow5^x\cdot624=3120\)

\(\Rightarrow5^x\cdot\dfrac{3120}{624}\)

\(\Rightarrow5^x=5\)

\(\Rightarrow5^x=5^1\)

\(\Rightarrow x=1\)

f) \(3\cdot4^{2x+1}-16^x=2816\)

\(\Rightarrow3\cdot4^{2x+1}-\left(4^2\right)^x=2816\)

\(\Rightarrow3\cdot4^{2x+1}-4^{2x}=2816\)

\(\Rightarrow4^{2x}\cdot\left(3\cdot4-1\right)=2816\)

\(\Rightarrow4^{2x}\cdot11=2816\)

\(\Rightarrow4^{2x}=\dfrac{2816}{11}\)

\(\Rightarrow4^{2x}=256\)

\(\Rightarrow\left(2^2\right)^{2x}=2^8\)

\(\Rightarrow2^{4x}=2^8\)

\(\Rightarrow4x=8\)

\(\Rightarrow x=2\)

Bài 2:

\(2^x+124=5^y\)

\(\Rightarrow5^y-2^x=124\)

\(\Rightarrow5^y-2^x=125-1\)

\(\Rightarrow\left\{{}\begin{matrix}5^y=125\\2^x=1\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}5^y=5^3\\2^x=2^0\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}y=3\\x=0\end{matrix}\right.\)

Vậy: .... 

Bài 3 :

a) 4.(x-5) - 2 ³=2⁴.3

4x-20-8=48

4x=76

x=19

b) 4.x³+15=271

4.x³=256

x³=64

=> x=4

c) ( 2x-3)²= 169

=> 2x-3= 13

2x=16

x=8

 Chúc bạn học tốt !

4*(x-5) - 2^3 = 2^4*3 

4*(x-5) - 8 = 16*3 

4*(x-5) - 8 = 48 

4*(x-5) = 48 + 8 

4*(x-5) = 56 

x- 5 = 56 : 4 

x - 5 = 14 

x = 14 + 5 

x = 19 

4*x^3 + 15 = 271 

4*x^3 = 271 - 15 

4*x^3 = 256 

x^3 = 256 : 4 

x^3 = 64 

x^3 = 4^3 

x = 4 

5.3^{x + 1} - 4.3^{x - 2} = 393

=> 5.3^x.3 - 4.3^x.1/3² = 393

=> 15.3^x - 4/9.3^x = 393

=> 3^x.(15 - 4/9)   = 393

=> 3^x . 131/9       = 393

=> 3^x                   = 393 : 131/9

=> 3^x                   = 27

=> 3^x                   = 3³

=> x                     = 3

\(\left(3^7:3^3+4\cdot3^2\right)\cdot3-2^2\cdot2^3\)
\(=\left(3^4+4\cdot9\right)\cdot3-2^5\)
\(=117\cdot3-32\)
\(=351-32=319\)

\(=\left(3^4+4.3^2\right).3-2^2.2^3\\ =\left(81+4.9\right).3-2^2.2^3\\ =117.3-2^5\\ =351-2^5=319\)

319 nha

8² : 4.3 +2.3²

= 64:4.3 + 2.9

= 16 . 3 + 18

= 48 + 18

= 66 

\(8^2:4.3+2.3^2\)

\(=64:4.3+2.9\)

\(=16.3+2.9\)

\(=48+2.9\)

\(=48+18\)

\(=66\)

a: =>48+338:(6x-5)^2=50

=>338:(6x-5)^2=2

=>(6x-5)^2=169

=>6x-5=13 hoặc 6x-5=-13

=>6x=-8 hoặc 6x=18

=>x=3 hoặc x=-4/3

b: =>120:[16-12(3x-74)]=81-21=60

=>16-12(3x-74)=2

=>12(3x-74)=14

=>3x-74=7/6

=>x=451/18

a: =>338:(6x-5)^2=25*2-48=2

=>(6x-5)^2=169

=>6x-5=13 hoặc 6x-5=-13

=>x=-4/3 hoặc x=3

b: =>120:[16-12(3x-74)]=81-21=60

=>16-12(3x-74)=2

=>12(3x-74)=14

=>3x-74=7/6

=>3x=451/6

=>x=451/18