Question

Tìm x:

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

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

c/172\(x^2-7^9:98^3=2^{-3}\)

Answer 1

a: \(\Leftrightarrow\left(\dfrac{12}{25}\right)^x=\dfrac{9}{25}-\dfrac{81}{625}=\dfrac{144}{625}\)

=>x=2

b: =>3x-1=-4

=>3x=-3

hay x=-1