I found width=13.72 ft and length=43.72 ft.
Call one dimension of the rectangle x, the other will be x+30
You want an area A=600 ft^2 but A=length x width=x*(x+30)=600
Rearranging you get:

solving this quadratic equation you get a negative solution and a positive one that gives your result.
1. Brandi was driving 60mph down the highway. Ratio is 60/1. 60mi per 1 hr
2. Brandi bought 5 apples at the store and 6 oranges. The ratio of apples to oranges is 5:6 or 5 to 6.
3. Brandi has 3 sisters and 1 brother. Ratio of sisters to brothers is 3:1 or 3 to 1.
4. Brandi has 20 shirts and 10 pants in her closet. The ratio of shirts to pants is 20:10 or 20 to 10.
5. Brandi has 12 boys in her class and 13 girls. The ratio of boys to girls is 12:13 or 12 to 13
Hope this helps:)
If your asking to multiply 9x5 then the anwser is 45.