Question

a) (\(\frac{1}{5}\))^3x-1=\(\frac{1}{25}\)

b) (\(\frac{4}{7}\))^x+2=\(\frac{7}{4}\)

c) (\(\frac{2}{3}\))^1-x=(\(\frac{2}{3}\))³

d)0,7^3x+1=(0,7)³

Answer 1

a)\(\left(\frac{1}{5}\right)^{3x-1}=\frac{1}{25}\)

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

<=> 3x-1=2

<=> 3x=3

<=> x=1

c) \(\left(\frac{2}{3}\right)^{1-x}=\left(\frac{2}{3}\right)^3\)

<=> 1-x=3

<=>x=-2

d) (0,7)^3x+1=(0,7)³

<=> 3x+1=3

<=> 3x=2

<=> x=2/3

Answer 2

b) \(\left(\frac{4}{7}\right)^{x+2}=\frac{7}{4}\)

\(\Leftrightarrow\left(\frac{4}{7}\right)^{x+2}=\left(\frac{4}{7}\right)^{-1}\)

<=> x+2=-1

<=> x=-3