( 19x + 2.52 ) : 14 = ( 13 - 8 )2- 4 2

( 19x + 2.52 ) : 14 = 52- 4 2

( 19x + 2.52 ) : 14 = 25- 16

( 19x + 2.52 ) : 14 =9

( 19x + 50 ) : 14 =9

 19x + 50=9 . 14

 19x + 50=126

19x=126-50

19x=76

x=76:19

x=4

(19x + 2.5²) : 14 = (13 - 8)² - 4²

(19x + 2.25) : 14 = 5² - 16

(19x + 50) : 14 = 25 - 16

(19x + 50) : 14 = 9

19x + 50 = 9 . 14

19x + 50 = 126

19x = 126 - 50

19x = 76

x = 76 : 19

x = 4

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

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

\(\left(19x+2\cdot5^2\right):14=9\)

\(19x+2\cdot5^2=9\cdot14=126\)

  \(19x+50=126\)

\(19x=126-50=76\)

\(x=\frac{76}{19}=4\)

b)   \(x+\left(x+1\right)+\left(x+2\right)+...+\left(x+30\right)=1240\)

\(\left(x+x+..+x\right)+\left(1+2+3+...+30=1240\right)\)(31 chữ số x)

\(31x+\frac{30\cdot31}{2}=1240\Leftrightarrow31x+465=1240\)

\(31x=1240-465=775\)

\(x=\frac{775}{31}=25\)

c) \(11-\left(-53+x\right)=97\)

\(11+53-x=97\Leftrightarrow64-x=97\)

\(x=64-97=-33\)

d) \(-\left(x+81\right)+213=-16\)

\(-x-81+213=-16\)

\(-x+132=-16\)

\(-x=-16-132=-148\)

\(x=148\)

..........

bn bị lộn ở câu d xem lại đi

a) \(\frac{3}{7}-\frac{1}{7}x=\frac{2}{3}\)

=> \(\frac{1}{7}x=\frac{3}{7}-\frac{2}{3}=-\frac{5}{21}\)

=> \(x=-\frac{5}{21}:\frac{1}{7}=-\frac{5}{21}\cdot7=-\frac{5}{3}\)

b) \(3x^2-2=72\)=> 3x² = 74 => x² = 74/3 => x không thỏa mãn

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

=> \(\left(19x+2\cdot25\right):14=5^2-4^2=9\)

=> \(\left(19x+50\right):14=9\)

=> \(19x+50=126\)

=> \(19x=76\)

=> x = 4

d) \(x:\frac{1}{2}+x:\frac{1}{4}+x:\frac{1}{8}+x:\frac{1}{16}+x:\frac{1}{32}=343\)

=> \(x\cdot2+x\cdot4+x\cdot8+x\cdot16+x\cdot32=343\)

=> \(x\left(2+4+8+16+32\right)=343\)

=> x . 62 = 343

=> x = 343/62

  Bài 1:

2^\(x\) = 4

2\(^x\) = 2²

 \(x=2\)

Vậy \(x=2\)

Bài 2:

2\(^x\) = 8

2\(^x\) = 2³

\(x=3\)

Vậy \(x=3\)

1. 5³ = 5.5.5 = 125

2. 2⁷ = 2.2.2.2.2.2.2 = 128

3. 4⁴ = 4.4.4.4 = 256

4. 7³ = 7.7.7 = 343

6. 3⁵ = 243

7. 2⁶ =  64

8. 3⁴ =  81

9. 8³ =  512

11. 13² = 169

12. 11² = 121

13. 14² = 196

14. 15² = 225

16. 17² = 289

17. 18² = 324

18. 19² = 361

19. 20² = 400

21. 10⁴ = 10000

22. 10⁵ = 100000

23. 10⁶ = 1000000

24. 10⁷ = 10000000

bạn làm như bạn gia hân là đúng nhé

\(3^2.3^x.81-27^4=0\)

\(3^2.3^x.3^4-\left(3^3\right)^4=0\)

\(3^6.3^x-3^{12}=0\)

\(3^6.3^x-3^{12}=0\)

\(3^6.3^x=0+3^{12}\)

\(3^6.3^x=3^{12}\)

\(3^{6+x}=3^{12}\)

\(\Rightarrow6+x=12\)

\(x=12-6\)

\(\Rightarrow x=6\)

\(2^{x+1}=4=2^2\Rightarrow x+1=2\Rightarrow x=1\)

\(2^{x-1}=4=2^2\Rightarrow x-1=2\Rightarrow x=3\)

\(2^x.4=128=4.32=4.2^5\Rightarrow x=5\)

\(3^{x-2}.9=81=9.9=9.3^2\Rightarrow x-2=2\Rightarrow x=4\)

\(\frac{3^{x+1}}{9}=3\Rightarrow3^{x+1}=27=3^3\Rightarrow x=2\)

\(41-2^x=9\Rightarrow2^x=41-9=32=2^5\Rightarrow x=5\)

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