Question

Shawna and her best friend Keisha go shopping. The function p(t) = 3x4 + 2x3 − 4x2 + 21 represents how much money each girl spent based on the number of hours they were shopping. If Shawna and Keisha each go shopping for 2 hours, how much money did they spend together?

Answer 1

Shawna and her best friend Keisha together spend $ 138

Solution:

Given that, Shawna and her best friend Keisha go shopping.

The function given for money each girl spent based on the number of hours they were shopping is:

`p(t)=3 x^(4)+2 x^(3)-4 x^(2)+21`

Find the amount of money that each girl spent

For t = 2 hours

`\begin{array}{l}{\mathrm{p}(2)=3(2)^(4)+2(2)^(3)-4(2)^(2)+21} \\\\ {\mathrm{p}(2)=3 * 16+2 * 8-4 * 4+21} \\\\ {\mathrm{p}(2)=48+16-16+21} \\\\ {\mathrm{p}(2)=69}\end{array}`

Find the amount of money that they spend together

Multiply by 2 the amount of money that each girl spent

`2 * 69 = 138`