13 sao trừ được 18 bạn xem có sai đề ko 

nếu sai đề gửi đề mới mình giải cho

a, ( 19X + 2 x 5² ) : 14 = ( 13 - 18 )² - 4²

( 19X + 2 x 5² ) : 14 = ( -5 )² - 4²

( 19X + 2 x 5² ) : 14 =  25  - 16

( 19X + 2 x 25 ) : 14 =  9

( 19X + 2 x 25 )  =  9 . 14

 19X + 2 x 25   = 126

19X  +  50     = 126

19X  = 126  - 50

19X  =  76

X     =  76 : 19  = 4

b, 2 x 3^X = 10 x 3¹² + 8 x 27⁴

2 x 3^X = 10 . 531441 + 8 . 531441

2 x 3^X = 2 x 3^X = 531441( 10+8)

2 x 3^X = 531441 . 18 = 9565938

  3^x    = 9565938 : 2  = 4782969

ma  3^( dungf mt ra tips keets quar )

Hok tot

13-18=-5

thì phải 

đúng k nhé

2.3^x= 10.3¹²+8.27⁴

2.3^x = 10.(3³)⁴+ (3³)⁴ . 8

2.3^x= (3³)⁴. 18

2.3^x= (3³)⁴.2.3²

2.3^x= 3¹²⁺².2

 2.3^x= 3¹⁴.2

=> x = 14

\(x\in\left(\infty;-\infty\right)\)

\(\frac{19x+50}{14}=\frac{9}{1}\Rightarrow\left(19x+50\right)1=14.9\)

\(\frac{\left(19x+50\right)1}{19x}=\frac{14.9}{19x}\)

\(\frac{19x+50}{19x}=\frac{14.19}{19x}\)

\(\Rightarrow x=4\)

a, \(\left(19.x+2.5^2\right)\div14=\left(13-8\right)^2-4^2\)

\(\left(19.x+2.25\right)\div14=5^2-4^2\)

\(\left(19.x+2.25\right)\div14=25-16\)

\(\left(19.x+50\right)\div14=9\)

\(\left(19.x+50\right)=9.14\)

\(19.x+50=126\)

\(19.x=126-50\)

\(19.x=76\)

\(\Rightarrow x=76\div19\)

\(\Rightarrow x=4\)

Vậy x = 4

b, \(2.3^x=10.3^{12}+8.27^4\)

\(2.3^x=10.3^{12}+8.\left(3^3\right)^4\)

\(2.3^x=10.3^{12}+8.3^{12}\)

\(2.3^x=\left(10+8\right).3^{12}\)

\(2.3^x=18.3^{12}\)

\(2.3^x=2.3^3.3^{12}\)

\(2.3^x=2.3^{15}\)

\(\Rightarrow x=15\)

Vậy x = 15

​ngu...~_~ bài ny mà cx nỏ bt làm : a ) x=4         b ) x=14

a) \(\left(19\cdot x+2\cdot5^2\right):14=\left(13-8\right)^2-4^2\)

\(\left(19\cdot x+50\right):14=9\)

\(19\cdot x+50=9\cdot14\)

\(19\cdot x+50=126\)

\(19\cdot x=126-50\)

\(19\cdot x=76\)

\(x=76:19\)

\(x=4\)

Vậy \(x=4\)

a)

\(\begin{array}{l}\left( {9x - {2^3}} \right):5 = 2\\9x - {2^3} = 2.5\\9x - 8 = 10\\9x = 18\\x = 2\end{array}\)

Vậy \(x = 2\)

b)

\(\begin{array}{l}\left[ {{3^4} - \left( {{8^2} + 14} \right):13} \right]x = {5^3} + {10^2}\\\left[ {81 - \left( {64 + 14} \right):13} \right]x = 125 + 100\\\left[ {81 - 78:13} \right]x = 125 + 100\\\left[ {81 - 6} \right]x = 225\\75x = 225\\x = 3\end{array}\)

Vậy \(x = 3\)

(x-1)^2:5^21=25^30.5

(x-1)^2=25^30.5.5^21

           =(5^2)^30.5^22

           = 5^60.5^22

(x-1)^2 =5^82

(x-1)^2=(5^41)^2

x-1=5^41

x=5^41+1

2.3^x+1=10.3^12+8:3^12

2.3^x+1=10+8=18

3^x+1=18/2=9

3^x+1=3^2

x+1=2

x=1

a) \(\left(19x+2\times5^2\right):14=\left(13-8\right)^2-4^2\)

\(\Rightarrow\left(19x+50\right):14=5^2-4^2=25-16=9\)

\(\Rightarrow19x+50=126\)

\(\Rightarrow19x=76\Rightarrow x=4\)

Vậy x = 4

b) \(2\times3^2=10\times3^{12}+8\times27^4\)

\(\Rightarrow2\times3^2=10\times\left(3^3\right)^4+8\times27^4\)

\(\Rightarrow2\times3^2=27^4\times\left(10+8\right)\)

\(\Rightarrow18=27^4\times18\)

\(\Rightarrow27^4\times18-18=0\Rightarrow18\times\left(27^4-1\right)=0\)

=> Không thấy biến x đâu cả

c) Ta thấy 3³ = 27

\(\Rightarrow3^{2x-5}=3^3\Rightarrow2x-5=3\Rightarrow2x=8\Rightarrow x=4\)

Vậy x = 4

d) \(3^{x+1}-x=80\Rightarrow3^{x+1}=81\)

Ta thấy 3⁴ = 81

\(\Rightarrow3^{x+1}=3^4\Rightarrow x+1=4\Rightarrow x=3\)

Vậy x = 3