Question 1022032
Let X by the number of 17" units, Y the number of 24" units.
{{{X+Y=12}}}<--- Quantity
{{{P=50X+70Y}}} <--- Profit
The extrema occur at the endpoints {{{X=0}}} and {{{X=12}}}.
{{{X=0}}}
{{{Y=12-0=12}}}
{{{P=50(0)+70(12)}}}
{{{P=840}}}
.
.
{{{X=12}}}
{{{Y=12-12=0}}}
{{{P=50(12)+70(0)}}}
{{{P=600}}}
Maximum profit is $840.