SOLUTION: Suppose there is a bus and on the bus are x girls. Each girl has x bags. In each bag are x cats. With each cat are x kittens. Suppose further that there are 29178 legs on the bus a

Algebra ->  Complex Numbers Imaginary Numbers Solvers and Lesson  -> Lesson -> SOLUTION: Suppose there is a bus and on the bus are x girls. Each girl has x bags. In each bag are x cats. With each cat are x kittens. Suppose further that there are 29178 legs on the bus a      Log On


   



Question 1023348: Suppose there is a bus and on the bus are x girls. Each girl has x bags. In each bag are x cats. With each cat are x kittens. Suppose further that there are 29178 legs on the bus and that all parties have the usual number of legs and that there is no drive on the bus. Find the value of x.
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
At the very first level are the x girls (each of which has 2 legs), so there are 2x legs.
At the second level are the x bags for each girl (but each bag has 0 legs), so there are 0%2Ax%5E2+=+0 legs.
At the third level are the x cats in each bag (each of which has 4 legs) , so there are x%2A%284x%5E2%29+=+4x%5E3 legs.
At the last level are the x kittens for each cat (each of which has 4 legs), so there are x%2A%284x%5E3%29+=+4x%5E4 legs.
Add everything up:
4x%5E4%2B4x%5E3%2B2x+=+29178 <==> 2x%5E4%2B2x%5E3%2Bx+=+14589
since we are expecting a whole number answer for x, a little brute force gives x = 9.
(By Descartes' rule of signs x = 9 will be the only positive root. The other real root would be negative, and the two others are complex.)