Question 147599
let x=speed of boat


d=rt __ t=d/r __ total time = time upstream + time downstream


3=[8/(x+2)]+[8/(x-2)] __ multiplying by (x+2)(x-2) __ 3x^2-12=16x


3x^2-16x-12=0 __ factoring __ (3x+2)(x-6)=0


3x+2=0 __ subtracting 2 __ 3x=-2 __ dividing by 3 __ x=-2/3 __ negative value not realistic


x-6=0 __ adding 6 __ x=6