Question

find two positive real numbers whose product is a maximum and whose sum is 154.

a)75,79
b)77,77
c)82,72
d)86,68
e)65,89

Answer 1

hii

Answer 2

A + B = 154
A = 154 - B
A*B = (154-B)*B = -B^2 + 154B
Use formula for finding line of symmetry of this parabola:
B = -154/-2 = 77
This value for B maximizes A*B.
By substitution
A = 154-77 =77
Therefore
A = 77, B = 77