<p>someone do this algebraically?</p>
<p>y=2x-8 what is the minimum value product xy could be?</p>
<p>THanks</p>
<p>is it -8?</p>
<p>ok well xy=min
so you substitute 2x-8 for y
you then have 2x^2-8x=min
take the derivative and set it equal to 0
4x-8=0
4x=8
x=2
then check whether it’s a min. left of 2:negative, right of 2:positive therefore it ios a min.
then plug 2 in the original equation (y=2x-8)
y= (2)(2)-8
y=-4
than multiply them together (-4)(2)=min
min=-8
So then yes you are right.</p>