JaritoDaFrito

sorry I dont think thats correct

First, you find the length and width which are 16 and 12. Using the Pythagorean theorem (a²+b²=c²) , you can figure it out. We know A and B, 16²+12²=c². Go on further and you get 256+144=c² then 400=c² and finally c=20. The diagonal is 20 units. 

sorry, I read the problem wrong the first time, the real answer is x≤−√3  or −1 < x ≤ √3

{THIS ANSWER IS WRONG, PLEASE READ MY SECOND ANSWER} You first multiply both sides by (x+1) and you get x+3=x²+x. You then subtract x from both sides and you get 3=x² which is $\sqrt{3}$=x.

22.5 square units