Question

BT1: Tìm x, biết:

7) \(\left(\dfrac{2}{3}-\dfrac{3}{5}x\right)^3=\dfrac{-64}{125}\)

Answer 1

cho mk sửa lại

tacó:

\(\dfrac{-64}{125}=\left(\dfrac{-4}{5}\right)^3\)

suy ra\(\dfrac{2}{3}-\dfrac{3}{5}x=\dfrac{-4}{5}\)

\(\dfrac{3}{5}x=\dfrac{2}{3}-\dfrac{-4}{5}\)

\(\dfrac{3}{5}x=\dfrac{22}{15}\)

\(x=\dfrac{22}{15}:\dfrac{3}{5}\)

\(x=\dfrac{22}{9}\)

Answer 2

ta có:

\(\dfrac{-64}{125}=\left(\dfrac{-16}{5}\right)^3\)

suy ra \(\dfrac{2}{3}-\dfrac{3}{5}x=\dfrac{-16}{5}\)

\(\dfrac{3}{5}x=\dfrac{2}{3}-\dfrac{-16}{5}\)

\(\dfrac{3}{5}x=\dfrac{58}{15}\)

\(x=\dfrac{58}{15}:\dfrac{3}{5}\)

\(x=\dfrac{58}{9}\)

Answer 3

tick cho mk với nha