Question

Tìm x biết:

(12/25)^x = (5/3)^-2 - (-3/5)⁴

Answer 1

( 12/25 )^x = ( 5/3 )^-2 - ( -3/5 )⁴

<=> ( 12/25 )^x = 9/25 - 81/625

<=> ( 12/25 )^x = 144/625

<=> ( 12/25 )^x = ( 12/25 )²

<=> x = 2

Answer 2

Bài làm:

Ta có: \(\left(\frac{12}{25}\right)^x=\left(\frac{5}{3}\right)^{-2}-\left(-\frac{3}{5}\right)^4\)

\(\Leftrightarrow\left(\frac{12}{25}\right)^x=\frac{9}{25}-\frac{81}{625}\)

\(\Rightarrow\left(\frac{12}{25}\right)^x=\frac{144}{625}\)

\(\Leftrightarrow\left(\frac{12}{25}\right)^x=\left(\frac{12}{25}\right)^2\)

\(\Rightarrow x=2\)

Answer 3

\(\left(\frac{12}{25}\right)^x=\left(\frac{5}{3}\right)^{-2}-\left(-\frac{3}{5}\right)^4\)

\(\left(\frac{12}{25}\right)^x=\frac{9}{25}-\frac{81}{625}\)

\(\left(\frac{12}{25}\right)^x=\frac{144}{625}\)

\(\left(\frac{12}{25}\right)^x=\left(\frac{12}{25}\right)^2\)

\(x=2\)

vậy \(x=2\)