The answer is: B. 11
Explanation:
1. The area of a rectangle is:
[tex]A=LW[/tex]
Where [tex]L[/tex] is the length and [tex]W[/tex] is the width.
2. The length of the rectangular-shaped deck is 5 meters longer than its width, therefore:
[tex]L=W+5[/tex]
3. You must substitute this into [tex]A=LW[/tex]:
[tex]66=(W+5)W\\W^{2}+5W-66=0[/tex]
4. Now you must solve for the width. You can use the Quadratic formula, which is:
[tex]W=\frac{-b+/-\sqrt{b^{2}-4ac}}{2a}[/tex]
Where:
[tex]a=1\\b=5\\c=-66[/tex]
5. Subsitute values:
[tex]W=\frac{-5+/-\sqrt{5^{2}-4(1)(-66)}}{2(1)}\\W=6[/tex]
6. Then, the lenght is:
[tex]L=6m+5m\\L=11m[/tex]
