Question 1200522
<br>
An exponential function is of the form {{{y=ab^x}}}.<br>
Plug in the given (x,y) values to get two equations in a and b:<br>
{{{ab^(-3)=5/27}}}
{{{ab^2=45}}}<br>
Divide the second equation by the first.<br>
{{{(ab^2)/(ab^(-3))=45/(5/27)=45*(27/5)=9*27=243}}}
{{{b^5=243=3^5}}}
{{{b=3}}}<br>
Substitute b=5 in either original equation to find a.<br>
{{{a(3^2)=45}}}
{{{9a=45}}}
{{{a=5}}}<br>
ANSWER: {{{y=5(3^x)}}}<br>