The given formula is
[tex] B = \frac{T-C}{C} [/tex]
Where B is the sales tax.
T is the total amount she paid for hat, and
C is the total cost of the hat .
In this question , we need to solve for T
We start with getting rid of the denominator C, by doing cross multiplication, that is
[tex] BC = T-C [/tex]
Now we need to get rid of the C that is in the right side and for that we add C .
[tex] BC+C=T [/tex]
It can also be written as
[tex] T=BC+C [/tex]
C is the common factor in the right side .
[tex] T= C(B+1) [/tex]
And that'sthe required answer .