Aturtle is at the bottom of a 20 foot well. each day it crawls up 4 feet but it slips back 2 feet. after how many days will the turtle reach the top of the well?

answer: evaluate the objective function at each vertex to determine which - and -values, if any, maximize or minimize the function. example: find the minimum value and maximum value of the objective function f ( x , y ) = 4 x + 5 y , subject to the following constraints