Here are some new distances with given lengths to help Cecil cross the tightrope, introduced in problem 2-50. Find at least two ways to get Cecil across. Write your solutions using numbers and symbols.

1. Span of tightrope: $21$ feet
   Given lengths: $3,5,8$ feet

   Hint (a):

   This problem is very similar to 2-55 on page 88 of your textbook. Use the solution to that problem to guide you, if you need help.

   More Help(a):

   Is $21$ a multiple of $3,5,$ or $8$? If so, try adding that to itself to get to $21$.
   That is a good starting place for the rest of the problem.

2. Span of tightrope: $12$ feet
   Given lengths: $4,7,9$ feet

   Hint (b):

   See part (a) for help.

   Answer (b):

   One possible solution is $7+9+(−4)$.

3. Span of tightrope: $16$ feet
   Given lengths: $3,5,7$ feet

   Hint (c):

   See part (a) for help.