x and y are the numbers
x+y=8
and product is max
xy=max
ok
x+y=8
minus x both sides
y=8-x
subsitute 8-x for y in other equation
(8-x)(x)=max
8x-x²=max
take derivitive
8-2x=dy/dx max
find where it equal 0
8-2x=0
8=2x
4=x
at x=4
y=8-x
y=8-4
y=4
the numbers are 4 and 4
their product is 4*4 or 16
