a) a^x-15 = 17

a^x=32

a^x=2^5

\(\Rightarrow\)x=5

Vậy x=5

b/       (7.x-11)^3  = 2^5.5^2+200

\(\Leftrightarrow\)(7.x-11)^3=800+200

\(\Leftrightarrow\)(7.x-11)^3= 1000

\(\Leftrightarrow\)(7x-11)^3= 10^3

\(\Leftrightarrow\) 7x-11=10

\(\Leftrightarrow\)7x=21

\(\Leftrightarrow\) x=3

Vậy x=3

a) a^x - 15 = 17

a^x = 17 + 15

a^x = 32

a^x = 2⁵

=> x = 5

Vậy x = 5

b) (7 . x - 11)³ = 2⁵ . 5² + 200

(7 . x - 11)³  = 32 . 25 + 200

(7 . x - 11)³ = 1000

(7 . x - 11)³ = 10³

=> 7 . x - 11 = 10

7 . x = 10 + 11

7 . x = 21

x = 21 : 7

x = 3

Vậy x = 3

Ủng hộ mk nha !!!  *_*

a)2^x-15=17

       2^x=17+15=32

       2^x=32=>x=5(vì 2^5=32)

b)mk ko bt cách giải

c)7^2-(15+x)=5.2^2

  49-(15+x)=5.4=20

       15+x=49-20

       15+x=29

 d)mk cx ko bt cách giải nhưng mk bt x=2(bn thử lại là bt)

b) (7x-11)³= 2⁵.5²+200

(7x-11)³ =  2⁵.5² + 2³.5²

(7x-11)³ = 2³.5²( 2²+1)

(7x-11)³ = 8 . 25 . 5

(7x-11)³  = 1000

(7x-11)³  = 10³

=> 7x-11 = 10

7x = 10+11

7x = 21

x= 3

d) (2x+1)³ = 125

(2x+1)³ = 5³

=> 2x + 1 = 5

=> 2x = 5-1

2x = 4

x=2

a ) 2 ^ x -15 = 17

     2 ^ x       = 17 + 15

     2 ^ x      = 32

     2 ^ x      = 2 ^ 5

     => x = 5

b ) ( 7x - 11 ) ^ 3 = 2 ^ 5 * 5 ^ 2 + 200

     ( 7x - 11 ) ^ 3 = 1000

     ( 7x - 11 ) ^ 3 = 10 ^ 3

    => 7x - 11 = 10

         7x        = 21

           x        = 3

2\(^x\)- 15 = 17

\(\Rightarrow\)2\(^x\) =  32

\(\Rightarrow\)x  = 5

2^x-15=17

=>2^x=17+15

=2^x=32

=>2^x=2^5

=>x=5

1,a) 695- [200+ (11- 1²)]

    = 695- [200+ (11- 1)]

    = 695- [200+ 10]

    = 695- 210

    = 485

  b) (5¹⁹: 5¹⁷+ 3): 7

   = (5²+ 3): 7

   = (25+ 3): 7

   = 28: 7

   = 4

  c) 129- 5[29- (6- 1²)]

   = 129- 5[29- (6- 1)]

   = 129- 5[29- 5]

   = 129- 5. 24

   = 129- 120

   = 9

3,a) 2x- 49= 5. 3²

       2x- 49= 5. 9

      2x- 49= 45

      2x     = 45+ 49

      2x     = 94

      x       = 94: 2

      x       = 47

  c) 2^x- 15= 17

     2^x       = 17+ 15

     2^x        = 32

     2^x      = 2⁵

 => x       = 5

Câu 3b bạn tự làm nhé, xin loiosxn vì không giúp được cả bài.

CHÚC BẠN HỌC GIỎI !!!

MÌNH TÌM RA CÁCH LÀM CÂU 3b RỒI !!!

5x+ 2x= 45+ 20: 15

5x+ 2x= 45+ \(\frac{4}{3}\)

5x+ 2x= \(\frac{139}{3}\)

(5+ 2)x=\(\frac{139}{3}\)

7x       =\(\frac{139}{3}\)

x         =\(\frac{139}{3}\): 7

x         =\(\frac{139}{21}\)

CHÚC BẠN HỌC GIỎI !!!

a, (6/11+5/11)x3/17

c1:=1x3/17

    =3/17

c2:=6/11x3/17+5/11x3/17

    =18/197+15/187

    =33/187

    =3/17

b,3/5x7/9-3/5x2/9

c1:=21/45-6/45

=15/45

=1/3

c2:=3/5x(7/9-2/9)

=3/5x5/9

=1/3

c,( 6/7-4/7):2/5

c1:=2/7:2/5

=2/7x5/2

=5/7

c2,6/7:2/5-4/7:2/5

=6/7x5/2-4/7x5/2

=15/7-10/7

=5/7

d,8/15:2/11+7/15:2/11

c1:=(8/15+7/15):2/11

=1x11/2

=11/2

c2:=8/15x11/2+7/15x11/2

=88/30+77/30

=165/30

=11/2

a) (\(\frac{6}{11}\) + \(\frac{5}{11}\)) x \(\frac{3}{17}\)=  \(\frac{11}{11}\) x \(\frac{3}{17}\)= \(1\) x\(\frac{3}{17}\)= \(\frac{3}{17}\)

b) \(\frac{3}{5}\)x\(\frac{7}{9}\)- \(\frac{3}{5}\)x \(\frac{2}{9}\) = \(\frac{3}{5}\)x (\(\frac{7}{9}\)- \(\frac{2}{9}\))= \(\frac{3}{5}\) x  \(\frac{5}{9}\)= \(\frac{3}{9}\)

c) (\(\frac{6}{7}\)- \(\frac{4}{7}\)) : \(\frac{2}{5}\)= \(\frac{2}{7}\) x \(\frac{5}{2}\)= \(\frac{5}{7}\)

d) \(\frac{8}{15}\) : \(\frac{2}{11}\) + \(\frac{7}{15}\): \(\frac{2}{11}\)=  ( \(\frac{8}{15}\)+ \(\frac{7}{15}\)) x \(\frac{11}{2}\)= 1 x \(\frac{11}{2}\)= \(\frac{11}{2}\)

Chúc học tốt nha!

a,3/17

b,1/3

c,5/7

d,11/2

chúc bạn hk tốt nhé(nhớ k cho tiu)