Question 982166

The sales tax in one state is {{{7}}}% or {{{0.07}}}. 
if selling price {{{x}}}, then tax will be {{{0.07x}}} 

then to find the total cost of a CD player with a selling price of ${{{x=150}}} you need to add the tax which is {{{0.07*150=10.50}}} and you have the total cost of a CD player

a function rule for finding the total cost will be

{{{f(x) =1*x+.07x}}}

{{{f(x) =1.07x}}} 

then you have

{{{f(x) =1.07*150}}}

{{{f(x) =160.50}}} 

so, your answer is  {{{f(x) =1.07x}}}; ${{{160.50 }}}