We have that 3 pencils cost $0.35, and 2 dozen pencils are 24 pencils, then we divide by 3 to know how many 3-pencils combo we can get:
![\begin{gathered} \frac{24}{3}=8 \\ \Rightarrow8\cdot(0.35)=2.8 \end{gathered}](https://tex.z-dn.net/?f=%5Cbegin%7Bgathered%7D%20%5Cfrac%7B24%7D%7B3%7D%3D8%20%5C%5C%20%5CRightarrow8%5Ccdot%280.35%29%3D2.8%20%5Cend%7Bgathered%7D)
therefore, 2 dozen pencils would cost $2.8
The correct answer is 3.2 x 10^-5
Change f(x) to a y and switch places with y and x as below.
![x= \frac{2}{3} y-6](https://tex.z-dn.net/?f=x%3D%20%5Cfrac%7B2%7D%7B3%7D%20y-6)
Solve the equation for y
![x + 6 = \frac{2}{3} y](https://tex.z-dn.net/?f=x%20%2B%206%20%3D%20%20%5Cfrac%7B2%7D%7B3%7D%20y)
Multiply each term by the reciprocal of
![\frac{2}{3}](https://tex.z-dn.net/?f=%20%5Cfrac%7B2%7D%7B3%7D%20)
![\frac{3}{2} (x+6) = y](https://tex.z-dn.net/?f=%20%5Cfrac%7B3%7D%7B2%7D%20%28x%2B6%29%20%3D%20y)
Distribute
![\frac{3}{2} x+9=y](https://tex.z-dn.net/?f=%20%5Cfrac%7B3%7D%7B2%7D%20x%2B9%3Dy)
Change y to
![f^{-1}(x)](https://tex.z-dn.net/?f=f%5E%7B-1%7D%28x%29)
21131 is to the nearest whole number