Question 431605
If the area of the rectangle is 16cm2, then L X W=16.  Also, 2L+2W=18.

2L+2W=18
2L=18-2W
L=9-W

Substituting for L, we get:

(9-W)W=16
9W-W2=16
0=W2-9W+16

*[invoke quadratic "x", 1, -9, 16 ]