SOLUTION: Together Mary and Sara can mow a golf course in 15 hours. Alone it takes Mary 2 hours less than Sara. Find the time it takes each of them to mow the course alone. PLEASE HELP!!!! t

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Together Mary and Sara can mow a golf course in 15 hours. Alone it takes Mary 2 hours less than Sara. Find the time it takes each of them to mow the course alone. PLEASE HELP!!!! t      Log On


   

Question 143248This question is from textbook algebra: structure and method: book1
: Together Mary and Sara can mow a golf course in 15 hours. Alone it takes Mary 2 hours less than Sara. Find the time it takes each of them to mow the course alone. PLEASE HELP!!!! the answer is m=29 and s=31, but I don't know how to get there. HELP APPRECIATED!!!! This question is from textbook algebra: structure and method: book1

Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
the time together is some fraction of the time alone __ the fractions add to 1 (the entire task)

let x=Mary, so x+2=Sara

(15/x)+[15/(x+2)]=1 __ multiplying by x(x+2) __ 15(x+2)+15x=x(x+2) __ 30x+30=x^2+2x

subtracting 30x+30 __ 0=x^2-28x-30

use quadratic formula to find x __ the answers are very close to (but not exactly) 29 and 31