We have cost = 12x+34y
Sales = (40-8x+5y)*x+ (50+9x-7y)*y
= 40x-8x2+5xy+50y+9xy-7y2
= -8x2+40x+14xy+50y-7y2
profit = sales - cost
= (-8x2+40x+14xy+50y-7y2 )-(12x+34y)
-8x2+28x+14xy+16y-7y2
d/dx = -16x+14y+28
d/dy = -14x+14y+16
Setting them to 0
16x-14y = 28........(1)
14x-14y. = -16.........(2)
Solving (2) from (1)
2x = 44
X = 22 (100 dollars)
Putting this value in (2)
14(22)-14y= -16
y = 324/14 = 23.14 (100 dollars)
MATICAL ASSOCIATION OF AMERICA NU Kwebwork / math242winter-hulbert / week 3b-7.3 optimizing functions.of several variables /7...
(7 10 Two connected tanks, each with a capacity of 60 liters, contain brine (salt water) Initially the firs tank contains 40 liters and the second tank contains 30 liers. Brine with a salt conccntration of 1 grams per litcr flows into the first tank at S litcrs per hour. Well-stirred brine flows from the first tank into the second at 7 liters per hour from the second nto the fist at3 lters per honr, from the first into a...