a) \(\frac{14}{15}:\frac{9}{10}=x:\frac{3}{7}\Rightarrow\frac{28}{27}=x:\frac{3}{7}\Rightarrow x=\frac{4}{9}\)

b) \(\left(x-\frac{4}{7}\right)^3=343\Rightarrow\left(x-\frac{4}{7}\right)^3=7^3\Rightarrow x-\frac{4}{7}=7\Rightarrow x=\frac{53}{7}\)

c) \(x^5=x^3\Leftrightarrow\hept{\begin{cases}x=1\\x=0\end{cases}}\)

e) \(\left(x-1\right)^4=16\Leftrightarrow\orbr{\begin{cases}\left(x-1\right)^4=2^4\\\left(x-1\right)^4=\left(-2\right)^4\end{cases}}\)\(\Leftrightarrow\orbr{\begin{cases}x-1=2\\x-1=\left(-2\right)\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=3\\x=-1\end{cases}}\)

Đề thiếu. Bạn coi lại đề.

x¹³=27x¹⁰

<=>x¹³-27x¹⁰=0

<=>x¹⁰(x³-27)=0

<=>x¹⁰(x-3)(x²+3x+9)=0

<=>\(\left[{}\begin{matrix}x^{10}=0\\x-3=0\\x^2+3x+9=0\end{matrix}\right.\)(I)

Dễ thấy x²+3x+9=0 vô nghiệm vì có \(\Delta=3^2-4.1.9=-27< 0\)

Do đó hệ (I) tương đương với:

\(\left[{}\begin{matrix}x=0\\x=3\end{matrix}\right.\)

Vậy S={0;3}.

   a  25 + 8 + 12 + 25 = 70            b  87 + [ - 750   ] + 2018 - 13 + 750 = 2842             c [ 45 + 12 - 13 ]  -  [ 45 - 13 + 12 ]  =  90                minh tinh gom bn ah

rk đúng hay sai đây

\(\dfrac{-8}{13}+\dfrac{-7}{17}+\dfrac{21}{13}\le x\le\dfrac{-9}{14}+3+\dfrac{5}{-14}\)

=> \(\dfrac{10}{17}\le x\le2\)

=> \(\dfrac{10}{17}\le\dfrac{17x}{17}\le\dfrac{34}{17}\)

=> 10 \(\le17x\le34\)
=> x = 1; 2 (thỏa mãn)
@Khánh Linh

(x+1)(x-2)(x-3)(2x-1)(3x-1)=0

\(x^{13}=27.x^{10}\)

\(x^{13}:x^{10}=27\)

\(x^3=27=3^3\)

\(\Rightarrow x=3\)