Đầu bài sai.

Sửa : 

\(\left(7x-11\right)^3=10000\)

\(\Rightarrow\left(7x-11\right)^3=10^3\)

\(\Rightarrow7x-11=10\)

\(\Rightarrow7x=21\)

\(\Rightarrow x=3\)

Tìm x ; e và N luôn !

 (7x-11)³=32*25+100

\(\Leftrightarrow\)(7x-11)³ = 900

\(\Leftrightarrow\)7x-11 = \(\sqrt[3]{900}\)

\(\Leftrightarrow\)x = \(\frac{\sqrt[3]{900}+11}{7}\)

a:  =>x-16=74

nên x=90

a) 2x + 23x = 625

   x (2 + 23) = 625

   x. 25        = 625

             x    = 625 : 25

             x    = 25

b) (2^2+4^2) x +2^4 x 5 * x = 100 (dấu* là dấu nhân vì mik không muốn trùng nhau nên viết vậy)

    ( 4 + 16 ) x + 2^4 x 5 * x = 100

         20 * x +   16 x 5 * x =100

            x ( 20 + 16 x 5 )  = 100

           x ( 20 + 80 ) = 100

           x * 100 =100

                   x=100 : 100

                   x= 1

c) ( 3x +1)^2 = 6^2+8^2

    (3x +1)^2  = 36 +64

    (3x +1)^2   =100

     (3x +1)^2  = 10^2

           3x + 1 =10

                  3x=10 - 1=9

                    x = 9 :3

                    x = 3

( d và e làm tương tự )

k mik nha!

Dể mà,k mik mik giải cho

Giai giup minh di ban

1) \(2^x-15=17\)

\(\Leftrightarrow2^x=32=2^5\)

\(\Rightarrow x=5\)

2) \(\left(7x-11\right)^3=25\cdot5^2+200\)

\(\Leftrightarrow\left(7x-11\right)^3=825\)

\(\Leftrightarrow7x-11=\sqrt[3]{825}\)

\(\Leftrightarrow7x=11+\sqrt[3]{825}\)

\(\Rightarrow x=\frac{11+\sqrt[3]{825}}{7}\)

3) \(\left(x+1\right)^{100}-3\left(x+1\right)^{99}=0\)

\(\Leftrightarrow\left(x+1\right)^{99}\left(x-2\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}\left(x+1\right)^{99}=0\\x-2=0\end{cases}}\Rightarrow\orbr{\begin{cases}x=-1\\x=2\end{cases}}\)

4) \(4x+5\left(x+3\right)=105\)

\(\Leftrightarrow9x+15=105\)

\(\Leftrightarrow9x=90\)

\(\Rightarrow x=10\)

5) \(5\cdot\left(x-2\right)+10\left(x+3\right)=170\)

\(\Leftrightarrow5\left[x-2+2\left(x+3\right)\right]=170\)

\(\Leftrightarrow3x+4=34\)

\(\Leftrightarrow3x=30\)

\(\Rightarrow x=10\)

cảm ơn bạn nhá NGUYỄN MINH ĐĂNG

\(\left(7x-11\right)^3=2^5.5^2+100\)

\(\left(7x-11\right)^3=800+100\)

\(\left(7x-11\right)^3=900\)

xg bạn tìm số nào mũ 3 lên thì đc 900 nhé, bạn tìm đc thì xuống dòng => 7x-11=....

b)

\(3^{x+3}-243=3^x\)

\(3^{x+3}-3^5=3^x\)

\(\Rightarrow x+3-5=x\)

\(\Rightarrow x+3=x+5\left(???\right)\)

`@` `\text {Ans}`

`\downarrow`

`(7x - 11)^2 = 2^5 * 5^2 + 100?`

`=> (7x - 11)^2 = 32*25 + 100`

`=> (7x - 11)^2 = 800 + 100`

`=> (7x - 11)^2 = 900`

`=> (7x - 11)^2 = (+-30)^2`

`=>`\(\left[{}\begin{matrix}7x-11=30\\7x-11=-30\end{matrix}\right.\)

`=>`\(\left[{}\begin{matrix}7x=41\\7x=-19\end{matrix}\right.\)

`=>`\(\left[{}\begin{matrix}x=\dfrac{41}{7}\\x=-\dfrac{19}{7}\end{matrix}\right.\)

Vậy, `x \in`\(\left\{\dfrac{41}{7};-\dfrac{19}{7}\right\}\)

Câu 1 : 

a) 7x-8=713

    7x=713+8

    7x=721

    x=721:7

   x=103

Vậy x=103.

b)2448:[119-(x-6)]=24

   119-(x-6)=2448:24

   119-(x-6)=102

   x-6=119-102

   x-6=17

  x=17+6

 x=23

Vậy x=23.

c) 2016-100(x+11)=2⁷:2³

   2016-100(x+11)=2⁴=16

  100(x+11)=2016-16

  100(x+11)=2000

  x+11=2000:100

 x+11=20

  x=20-11

  x=9

Vậy x=9.

Câu 2 :

879.2+879.996+3.879=879(2+996+3)

                                   =879.1001

                                   =879879

a, \(3^x.4=324\)

\(\Rightarrow\) \(3^x=81\)

\(\Rightarrow\) \(3^x=3^4\)

\(\Rightarrow\) \(x=4\)

b, \(x^{100}=x\)

\(\Rightarrow\orbr{\begin{cases}x=1\\x=0\end{cases}}\)

c, \(\left(3x-1\right)^3=125\)

\(\Rightarrow\) \(\left(3x-1\right)^3=5^3\)

\(\Rightarrow\) \(3x-1=5\)

\(\Rightarrow\) \(3x=6\)

\(\Rightarrow\) \(x=2\)

d, \(2x-15=17\)

\(\Rightarrow\) \(2x=32\)

\(\Rightarrow\)\(x=16\)