Question 107483
let x="rate in still water" ... t=d/r ... 60/(x-3)+60/(x+3)=9 ... 60(x+3)+60(x-3)=9(x+3)(x-3)


120x=9x^2-81 ... 0=9x^2-120x-81 ... 0=3x^2-40x-27


use quadratic equation to find x