4x99=396in
1 yard=36 in
so there for mandy needs 11 yards of trim
14/70 in it's simplest form is 1/5
hope this helps :)
For b it's 39 because you multiply 5 and 7 giving you 35 then add 4 Wich equals 39. I might be incorrect. check it out.
Please see the answer here
http://www.wolframalpha.com/input/?i=y%5E-1%20dy%20%2Bye%5E%28cosx%29%20sinxdx%3D0