Question

The equation t(x)=x+0.029x models the total cost of an item, in dollars, where x is the cost before sales tax. What is the total cost of a $20 item?

Answer 1

The above answer is correct. = 20.58

Answer 2

In order to calculate that, you need to substitute for x = 20
t(20) = 20 + 0.029(20)
t(20) = 20 + 0.58
t(20) = 20.58

In short, Your Answer would be 20.58

Hope this helps!