Question 73356
Let x=width of parking lot
Then x+3=length of parking lot

Area of rectangle equals Length times Width.  So our equation to solve is:
{{{180=x(x+3)}}}  get rid of parens

{{{180=x^2+3x}}} subtract 180 from both sides

{{{x^2+3x-180=0}}}  quadratic in standard form
A=1
B=3
C=-180

We will solve using the quadratic formula:
{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}
{{{x = (-3 +- sqrt( 3^2+4*180 ))/(2) }}}
{{{x = (-3 +- sqrt( 9+720 ))/(2) }}}
{{{x = (-3 +- sqrt( 729))/(2)}}}
{{{x = (-3 +- 27)/(2)}}}
{{{x=-30/2=-15}}}-------------------------discount the negative value for length
{{{x=+24/2=12 yds}}} -------------------------width of field
{{{x+3=12+3=15 yds}}}---------------------------length of field

CK

15*12=180
180=180
also 15 is 3 more than 12

Hope this helps---ptaylor