Shawna and her best friend Keisha go shopping.
The function p(x) = 3x^4 + 2x^3 − 4x^2 + 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?

$37
$69
$101
$138