X=4/15:2/5=2/3

2/3

X = 4/5 : 2/15

X = 2/3

x/30 + 4/5= 79/30

x/30 = 79/30 - 4/5

x/30= 11/6

11/6= 55/30

=> x= 55

\(x^{15}=x\)

\(\Rightarrow x^{15}-x=0\)

\(\Rightarrow x.\left(x^{14}-1\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x=0\\x^{14}-1=0\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=0\\x^{14}=0+1=1\end{cases}}\)

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

Ta có : x : x¹⁵ = x 

<=> x = x¹⁶

=> x = 1 ; 0 

\(x+\left(x+1\right)+\left(x+2\right)+...+19+20=20\)

\(\Leftrightarrow x+\left(x+1\right)+\left(x+2\right)+...+19=0\)

\(\Leftrightarrow\frac{x\left(19+x\right)}{2}=0\)

\(\Leftrightarrow x\left(x+19\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}x=0\\x+19=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=0\\x=-19\end{cases}}\)

Mà \(x\ne0\)nên \(x=-19\)

x:x+9<xX5<20

1+9<xX5<20

10<xX5<20

2X5<xX5<4X5

x=3

=98 nha ban

X=3 nha bạn

a, = 76 + 30 - 5

= 101

b, x - 2,751 = 15,12

x = 15,12 + 2,751 

x = 17,871

=>x-4368=13936

hay x=18304

\(x-\dfrac{4}{12}=-\dfrac{5}{6}\)

⇔\(x-\dfrac{1}{3}=-\dfrac{5}{6}\)

⇔\(x=-\dfrac{1}{2}\)

\(\Leftrightarrow x=-\dfrac{1}{2}\)

=>(x-4).6=12.(-5)

=>6x-24=-60

=>6x=-36

=x=-6

\(x-\dfrac{1}{4}=\dfrac{-21}{10}\)

\(x=\dfrac{-21}{10}+\dfrac{1}{4}\)

\(x=\dfrac{-42}{20}+\dfrac{5}{20}=\dfrac{-37}{20}\)