31 gallons of gas cost $82.15. what is the unit rate for 1 gallon of gas a.$2.65 per gallon b.$3.08 per gallon c.$265.00 per gallon d.$308.00

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