Question

Bài 1: Tìm x , biết :

a. 172 . x²- 7⁹: 98³ = \(\left(\dfrac{1}{2}\right)^3\)

b. (5x + 1)² = \(\dfrac{36}{49}\)

c, \(\left(x-\dfrac{2}{3}\right)^3\)= \(\left(\dfrac{2}{3}\right)^6\)

Answer 1

b, \(\left(5x+1\right)^2=\dfrac{36}{49}\)

\(\left(5x+1\right)^2=\left(\pm\dfrac{6}{7}\right)^2\)

\(\Rightarrow\left[{}\begin{matrix}5x+1=\dfrac{6}{7}\\5x+1=-\dfrac{6}{7}\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}5x=-\dfrac{1}{7}\\5x=\dfrac{-13}{7}\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=-\dfrac{1}{35}\\x=\dfrac{-13}{35}\end{matrix}\right.\)

Vậy .....

Answer 2

Nguyễn Thanh Hằng ;Hồng Phúc Nguyễn ;Mới vô; ... các bn giúp mik vs mik đang cần gấp !