Question 83765

Let w=width

Then length=w+6

Now we know that the area (A) of a rectangle =l*w, so our equation to solve is:

72=(w+6)*w  get rid of parens

72=w^2+6w  subtract 72 from both sides

w^2+6w-72=0--------------quadratic in standard form and this quadratic can be factored.  The factors are:

(w+12)(w-6)=0
(note:  If the A coefficient of a quadratic is 1, then the B coefficient is the sum of the factors of the C coefficient.  In this case(12)(-6)=-72 and 12-6=6) 

w=-12--------discount negative value for length

w=6 ft--------------------------------width of room
w+6=6+6=12 ft--------------------------------length of room

CK
6*12=72
72=72
also
12-6=6
6=6


Hope this helps----ptaylor