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

Answer: 138$ I just took the test.

Answer 2

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

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

Find the amount of money that they spend together

Multiply by 2 the amount of money that each girl spent

$2 \times 69 = 138$