Question 1118618
{{{90x+3x^2=3000}}}

{{{x(90+3x)=3000}}},  width being x, and length being  3x+90

-


{{{x(30+x)=1000}}}------find maybe two wholenumber factors differing by 30?


{{{1000=100*10=4*25*10=4*25*2*5=40*25=20*50}}}-------last two differ by 30;

{{{x^2+30x-1000=0}}}
{{{(x-20)(x+50)=0}}}
{{{highlight(x=20)}}}-------width
-
Length, {{{3x+90}}}
{{{3*20+90}}}
{{{highlight(150)}}}---------length




Otherwise general solution for quadratic equation:

{{{x^2+30x-1000=0}}}
{{{x=(-30+sqrt(900+4000))/2}}}
{{{x=(-30+sqrt(4900))/2}}}
{{{x=(-30+70)/2}}}
{{{x=40/2}}}
{{{x=20}}}