Question 143248
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