Question

Mong mn giúp mik bài này vs ạ!
Bài 1: Tìm x biết:
a) (x + 5)³ = \(\dfrac{8}{27}\)
b) (x - 2)² = \(\dfrac{25}{9}\)
c) (x - 1)⁴ = \(\dfrac{81}{16}\)
d) (2x - 1)⁵ = \(\dfrac{-1}{32}\)
e) (3x - 2)³ = -64
g) (\(\dfrac{1}{3}\)x + \(\dfrac{1}{5}\))² = \(\dfrac{49}{25}\)
Mong mn giúp mik ạ! Trân trọng cẻm ơn

Answer 1

a: =>x+5=2/3

hay x=-13/3

b: =>x-2=5/3 hoặc x-2=-5/3

=>x=1/3 hoặc x=11/3

c: =>x-1=3/2 hoăc x-1=-3/2

=>x=5/2 hoặc x=-1/2

Answer 2

a. ... \(\Leftrightarrow x+5=\dfrac{2}{3}\Leftrightarrow x=-\dfrac{13}{3}\)

b. ... \(\Leftrightarrow\left[{}\begin{matrix}x-2=\dfrac{5}{3}\\x-2=-\dfrac{5}{3}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{11}{3}\\x=\dfrac{1}{3}\end{matrix}\right.\)

c. ... \(\Leftrightarrow\left[{}\begin{matrix}x-1=\dfrac{3}{2}\\x-1=-\dfrac{3}{2}\end{matrix}\right.\)  \(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{5}{2}\\x=-\dfrac{1}{2}\end{matrix}\right.\)

d. ... \(\Leftrightarrow2x-1=-\dfrac{1}{2}\Leftrightarrow x=\dfrac{1}{4}\)

e. ... \(\Leftrightarrow3x-2=-4\Leftrightarrow x=-\dfrac{2}{3}\)

g. ... \(\Leftrightarrow\left[{}\begin{matrix}\dfrac{1}{3}x+\dfrac{1}{5}=\dfrac{7}{5}\\\dfrac{1}{3}x+\dfrac{1}{5}=-\dfrac{7}{5}\end{matrix}\right.\)  \(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{18}{5}\\x=-\dfrac{24}{5}\end{matrix}\right.\)