Question 148073
length=L
width=W

LW=720000

2L+W=2500

then

L(2500-2L)=720000

-2L^2+2500L-720000=0

2L^2-2500L+720000=0

{{{L = (2500 +- sqrt( 2500^2-4*2*720000 ))/(2*2) }}}=
 {{{L = (2500 +- sqrt(490000 ))/(4) }}}=
{{{L = (2500 +- 700)/(4) }}}=

L=800 or L=450

then L=800 and W=900
or
L=450 and W=1600