
Finding the diagonal
The width of a rectangle is 2 less than twice its length. If the area of the rectangle is 54 cmhttp://webwork.rutgers.edu/webwork2_...a0072fb581.png, what is the length of the diagonal?
Note: Your answer must be a number. It may not contain any arithmetic operations.
For this i have done:
A = lw
so
54= l ( 2l  2)
54= (2l^2  2l)
54 = 2l ( l 1)
This seems wrong...

Re: Finding the diagonal
Looks OK to me, solve using the quadratic formula.

Re: Finding the diagonal
so set it all equal to 0?
would it be
0= 2l^2  2l  54?

Re: Finding the diagonal
OK, I got l = 5.72 and w = 9.44
and now i just do pythagorean theorem to find the diagonal :D
thanks! :D