a) x=60

b) x=107

f) x=2

.....

CHO MÌNH BIẾT CẢ CÁCH LÀM NHA

a) 315 + ( 146 - x ) = 401

<=> 146 - x = 401 - 315

<=> 146 - x = 86

<=> x = 60

Vậy x  = 60

Giải:

\(a,2^x-15=17.\)

\(2^x=17+15.\)

\(2^x=32.\)

\(2^x=2^5.\)

\(\Rightarrow x=5\in N.\)

Vậy \(x=5.\)

\(b,\left(7x-11\right)^3=2^5.5^2+200.\)

\(\left(7x-11\right)^3=32.25+200.\)

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

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

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

\(\Rightarrow7x-11=10.\)

\(\Rightarrow7x=10+11=21.\)

\(\Rightarrow x=21:7=3\in N.\)

Vậy \(x=3.\)

\(c,3^x+25=26.2^2+2.3^0.\)

\(3^x+25=26.2^2+2.1.\)

\(3^x+25=2\left(26.2+1\right).\)

\(3^x+25=2.53.\)

\(3^x+25=106.\)

\(3^x=106-25.\)

\(3^x=81.\)

\(3^x=3^4\Rightarrow x=4\in N.\)

Vậy \(x=4.\)

\(d,49.7^x=2041.\)(đề này sai).

Sửa đề:

\(49.7^x=2401.\)

\(7^x=2401:49.\)

\(7^x=49.\)

\(7^x=7^2\Rightarrow x=2\in N.\)

Vậy \(x=2.\)

\(e,3^x=243.\)

\(3^x=3^5\Rightarrow x=5\in N.\)

Vậy \(x=5.\)

~ Học tốt!!! ~

a, \(2^x-15=17\)

\(\Rightarrow2^x=32\Rightarrow2^x=2^5\)

Vì \(2\ne-1;2\ne0;2\ne1\) nên \(x=5\)

Vậy....

b, \(\left(7x-11\right)^3=2^5.5^2+200\)

\(\Rightarrow\left(7x-11\right)^3=32.25+200\)

\(\Rightarrow\left(7x-11\right)^3=1000=10^3\)

\(\Rightarrow7x-11=10\Rightarrow7x=21\Rightarrow x=3\)

Vậy.....

c, \(3^x+25=26.2^2+2.3^0\)

\(\Rightarrow3^x+25=26.4+2\)

\(\Rightarrow3^x=104+2-25\)

\(\Rightarrow3^x=81=3^4\)

Vì \(3\ne-1;3\ne0;3\ne1\) nên x=4

Vậy.....

d,Sửa đề:\(49.7^x=2401\)

\(\Rightarrow7^2.7^x=7^4\Rightarrow7^{2+x}=7^4\)

Vì \(7\ne-1;7\ne0;7\ne1\) nên \(2+x=4\Rightarrow x=2\)

Vậy.....

Câu e làm tương tự! Chúc bạn học tốt!!!

1) \(2^x-15=17\)

\(2^x=17+15=32=2^5\)

\(\Rightarrow x=5\)

2) \(\left(7x-11\right)^3=2^5.5^2+200=32.25+200=1000=10^3\)

\(\Rightarrow7x-11=10\)

\(7x=11+10=21\)

\(x=3\)

3) \(3^x+25=26.2^2+2.3^0=26.4+2=106\)

\(3^x=106-25=81=3^4\)

\(\Rightarrow x=4\)

4) \(49.7^x=2041\)

\(7^2.7^x=7^4\)

\(\Rightarrow2+x=4\)

x = 2.

5) \(3^x=243=3^5\)

\(\Rightarrow x=5\)

a) \(\dfrac{2}{3}x-\dfrac{1}{2}=\dfrac{1}{10}\)

\(\dfrac{2}{3}x=\dfrac{1}{10}+\dfrac{1}{2}=\dfrac{3}{5}\)

\(x=\dfrac{3}{5}:\dfrac{2}{3}=\dfrac{9}{10}\)

b) \(\dfrac{39}{7}:x=13\)

\(x=\dfrac{\dfrac{39}{7}}{13}=\dfrac{3}{7}\)

c) \(\left(\dfrac{14}{5}x-50\right):\dfrac{2}{3}=51\)

\(\dfrac{14}{5}x-50=51\cdot\dfrac{2}{3}=34\)

\(\dfrac{14}{5}x=34+50=84\)

\(x=\dfrac{84}{\dfrac{14}{5}}=30\)

d) \(\left(x+\dfrac{1}{2}\right)\left(\dfrac{2}{3}-2x\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x+\dfrac{1}{2}=0\\\dfrac{2}{3}-2x=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{1}{2}\\x=\dfrac{1}{3}\end{matrix}\right.\)

e) \(\dfrac{2}{3}x-\dfrac{1}{2}x=\dfrac{5}{12}\)

\(\dfrac{1}{6}x=\dfrac{5}{12}\)

\(x=\dfrac{5}{12}:\dfrac{1}{6}=\dfrac{5}{2}\)

g) \(\left(x\cdot\dfrac{44}{7}+\dfrac{3}{7}\right)\dfrac{11}{5}-\dfrac{3}{7}=-2\)

\(\left(x\cdot\dfrac{44}{7}+\dfrac{3}{7}\right)\cdot\dfrac{11}{5}=-2+\dfrac{3}{7}=-\dfrac{11}{7}\)

\(x\cdot\dfrac{44}{7}+\dfrac{3}{7}=-\dfrac{11}{7}:\dfrac{11}{5}=-\dfrac{5}{7}\)

\(\dfrac{44}{7}x=-\dfrac{5}{7}-\dfrac{3}{7}=-\dfrac{8}{7}\)

\(x=-\dfrac{8}{7}:\dfrac{44}{7}=-\dfrac{2}{11}\)

h) \(\dfrac{13}{4}x+\left(-\dfrac{7}{6}\right)x-\dfrac{5}{3}=\dfrac{5}{12}\)

\(\dfrac{25}{12}x-\dfrac{5}{3}=\dfrac{5}{12}\)

\(\dfrac{25}{12}x=\dfrac{5}{12}+\dfrac{5}{3}=\dfrac{25}{12}\)

\(x=1\)

Mỏi tay woa bn làm nốt nha!!

x^20-x=0

x(x^19-1)=0

x= 0 

hoặc x ^ 19 =1

x = 0 hoặc x= 1

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

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

Câu 1: 

a: =>-2x-x+17=34+x-25

=>-3x+17=x+9

=>-4x=-8

hay x=2

b: =>17x+16x+27=2x+43

=>33x+27=2x+43

=>31x=16

hay x=16/31

c: =>-2x-3x+51=34+2x-50

=>-5x+51=2x-16

=>-7x=-67

hay x=67/7

e: 3x-32>-5x+1

=>8x>33

hay x>33/8

a) 2^x - 15 = 17

<=> 2^x = 2

<=> x = 1

b) ( 7x - 11 )³ = 2⁵.5² + 200

<=> ( 7x - 11 )³ = 800 + 200

<=> ( 7x - 11 )³ = 10³

<=> 7x - 11 = 10

<=> 7x = 21

<=> x = 3

c) x¹⁰ = 1^x

<=> x = 0 hoặc 1

d) x¹⁰ = x

<=> x = 0 hoặc 1

e) ( x - 1 )³ = 27

<=> ( x - 1 )³ = 3³

<=> x - 1 = 3

<=> x = 4

a) 2^x - 15 = 17

2^x=17+15

2^x=32

2^x=2⁵

=>x=5