a)\(\left(\frac{3}{5}\right)^5\times x=\left(\frac{3}{7}\right)^7\)

\(\Leftrightarrow\frac{3^5}{5^5}\times x=\frac{3^7}{7^7}\)

\(\Leftrightarrow x=\frac{3^7}{7^7}:\frac{3^5}{5^5}\)

\(\Leftrightarrow x=\frac{3^7\times5^5}{7^7\times3^5}\)

\(\Leftrightarrow x=\frac{3^2\times5^5}{7^7}\)

b)\(\left(\frac{-1}{3}\right)^3\times x=\frac{1}{81}\)

\(\Leftrightarrow\frac{\left(-1\right)^3}{3^3}\times x=\frac{1}{3^4}\)

\(\Leftrightarrow x=\frac{1}{3^4}:\frac{-1}{3^3}\)

\(\Leftrightarrow x=\frac{1\times3^3}{3^4\times\left(-1\right)}\)

\(\Leftrightarrow x=\frac{1}{-3}\)

c)\(\Leftrightarrow\left(x-\frac{1}{2}\right)^3=\left(\frac{1}{3}\right)^3\)

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

\(\Leftrightarrow x=\frac{1}{3}+\frac{1}{2}\)

\(\Leftrightarrow x=\frac{5}{6}\)

d)\(\Leftrightarrow\left(x+\frac{1}{2}\right)^4=\left(\frac{2}{3}\right)^4\)

\(\Leftrightarrow x+\frac{1}{2}=\frac{2}{3}\)

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

\(\Leftrightarrow x=\frac{1}{6}\)

a, \(x=\dfrac{3}{4}-1=\dfrac{3}{4}-\dfrac{4}{4}=-\dfrac{1}{4}\)

b, \(x=\dfrac{1}{5}-4=\dfrac{1}{5}-\dfrac{20}{5}=-\dfrac{19}{5}\)

c, \(x=2+\dfrac{1}{5}=\dfrac{10}{5}+\dfrac{1}{5}=\dfrac{11}{5}\)

d, \(x=\dfrac{1}{81}-\dfrac{5}{3}=\dfrac{1}{81}-\dfrac{135}{81}=-\dfrac{134}{81}\)

\(a,\dfrac{3}{4}-x=1\\ \Rightarrow x=1,75\\ b,x+4=\dfrac{1}{5}\\ \Rightarrow x=-3,8\\ c,x-\dfrac{1}{5}=2\\ \Rightarrow x=2,2\\ d,x+\dfrac{5}{3}=\dfrac{1}{81}\\x=\dfrac{1}{81}-\dfrac{5}{3}\\ \Rightarrow x=-\dfrac{134}{81}\)

a) \(\dfrac{3}{4}-x=1\)

\(x=\dfrac{3}{4}-1\)

\(x=-\dfrac{1}{4}\)\(=0,25\)

b) \(x+4=\dfrac{1}{5}\)

\(x=\dfrac{1}{5}-4\)

\(x=-\dfrac{19}{5}\)\(=-3,8\)

c) \(x-\dfrac{1}{5}=2\)

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

\(x=\dfrac{11}{5}=2,2\)

d) \(x+\dfrac{5}{3}=\dfrac{1}{81}\)

\(x=\dfrac{1}{81}-\dfrac{5}{3}\)

\(x=-\dfrac{134}{81}\)

tu hoc moi gioi

\(\left(x+4\right)^2-81=0\Leftrightarrow\left(x+4\right)^2-9^2=0\)

\(\Leftrightarrow\left(x+4+9\right)\times\left(x+4-9\right)=0\)

\(\Leftrightarrow\left(x+13\right)\times\left(x-5\right)=0\)

\(\left[{}\begin{matrix}x+13=0\\x-5=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-13\\x=5\end{matrix}\right.\)

1+2+3+....+999

=\(\frac{999.\left(999+1\right)}{2}\)

=999000/2

=499500

x^2.x^4.x^6.x^8....x^48...x^50

=x^{(2+4+6+8+...+48+50)}

=x⁶⁵⁰

tìm X 

5^x=125

5^x=5^3

x=3

3^2x=81

3^2x=3^4

2x=4

x=4:2

x=2

**** nhé

  Bài 1:

2^\(x\) = 4

2\(^x\) = 2²

 \(x=2\)

Vậy \(x=2\)

Bài 2:

2\(^x\) = 8

2\(^x\) = 2³

\(x=3\)

Vậy \(x=3\)

Bài 3

2\(^x\) = 16

2\(^x\) = 2⁴

  \(x=4\)

Vậy \(x=4\)

1: =>5(2x+6)=40

=>2x+6=8

=>2x=2

=>x=1

2: =>12-(x+3)=256:64=4

=>(x+3)=8

=>x=5

3: =>2x-1=3 hoặc 2x-1=-3

=>x=2 hoặc x=-1

4: \(\Leftrightarrow3^{x+2017}=3^{2015}\)

=>x+2017=2015

=>x=-2

1: =>5(2x+6)=40

=>2x+6=8

=>2x=2

=>x=1

2: =>12-(x+3)=256:64=4

=>(x+3)=8

=>x=5

3: =>2x-1=3 hoặc 2x-1=-3

=>x=2 hoặc x=-1

4: \Leftrightarrow3^{x+2017}=3^{2015}⇔3x+2017=32015

=>x+2017=2015

=>x=-2