The given function is:
\(\displaystyle{b}{\left({x}\right)}={13}{\left({0.7}\right)}^{{x}}\)

Is in the form: \(\displaystyle{y}={a}{\left({b}\right)}^{{x}}\)

Since b=0.7

Then the function represents exponential decay.

Is in the form: \(\displaystyle{y}={a}{\left({b}\right)}^{{x}}\)

Since b=0.7

Then the function represents exponential decay.