Question

tìm x

\(\left(\frac{-3}{4}\right)^{3x-1}\) = \(\frac{256}{81}\)

Answer 1

\(\left(\frac{-3}{4}\right)^{3x-1}=\frac{256}{81}\)

\(\Rightarrow\left(\frac{-3}{4}\right)^{3x}:\left(\frac{-3}{4}\right)=\frac{256}{81}\)

\(\Rightarrow\left(\frac{-3}{4}\right)^{3x}=\frac{256}{81}.\left(\frac{-3}{4}\right)\)

\(\Rightarrow\left(\frac{-3}{4}\right)^{3x}=\frac{64}{27}\)

\(\Rightarrow\left(-\frac{3}{4}\right)^{3x}=\left(-\frac{4}{3}\right)^3\)

\(\Rightarrow1=\left(-\frac{4}{3}\right)^3.\left(-\frac{4}{3}\right)^{3x}\)

\(\Rightarrow1=\left(-\frac{4}{3}\right)^{-x}\)

\(\Rightarrow1=\left(-\frac{3x}{4}\right)\)

\(\Rightarrow1=-3x:4\)

\(\Rightarrow-3x=4\)

\(\Rightarrow x=-\frac{4}{3}\)

Answer 2

Ta có:

\(\frac{256}{81}=\frac{4^4}{"-3"^4}=\frac{1}{\frac{"-3"^4}{4}}=\frac{1}{"\frac{-3}{4}"^4}="\frac{-3}{4}"^4="\frac{-3}{4}"^{3x-1}\Rightarrow3x-1=-4\Rightarrow3x=-4+1\)

\(=-3\)

\(\Rightarrow x=-3:1=-1\)

Answer 3

tớ làm bừa đấy sai thì thôi nha

Answer 4

ko sao bn ạ