Question

Tìm x , biết : 

( 3x -2 ) ^5 = -243

 

Answer 1

\(\left(3x-2\right)^5=-243\)

\(\Leftrightarrow\left(3x-2\right)^5=-3^5\)

\(\Leftrightarrow3x-2=-3\)

\(\Leftrightarrow3x=-1\)

\(\Leftrightarrow x=-\frac{1}{3}\)

Answer 2

\(\left(3x-2\right)^5=-243\)

\(\Leftrightarrow\left(3x-2\right)^2=\left(-3\right)^5\)

\(\Rightarrow3x-2=-3\)

\(\Rightarrow3x=-3+2\)

\(\Rightarrow3x=-1\)

\(\Rightarrow x=-\frac{1}{3}\)

Answer 3

\(\left(3x-2\right)^5=-243\)
\(\Leftrightarrow\left(3x-2\right)^5=-3^5\)
\(\Leftrightarrow3x-2=-3\)
\(\Leftrightarrow3x=-1\)
\(\Leftrightarrow x=\frac{-1}{3}\)
\(\text{Vậy }x=\frac{-1}{3}\)