SOLUTION: two fishing boats depart a harbor at the same time, one traveling east, the other south. the eastbound boat travels at a speed 3 mi/h faster then the southbound boat. after two hou

Algebra ->  Equations -> SOLUTION: two fishing boats depart a harbor at the same time, one traveling east, the other south. the eastbound boat travels at a speed 3 mi/h faster then the southbound boat. after two hou      Log On


   

Question 564723: two fishing boats depart a harbor at the same time, one traveling east, the other south. the eastbound boat travels at a speed 3 mi/h faster then the southbound boat. after two hours the boats are 30 mi apart. find the speed of the southbound boat
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
they are travelling at right angles to each other.
At any given instant they form a right triangle with their starting point

speed of DISABLED_event_one= x South bound
other speed = x+3 East bound
after two hours
they will be 2x & 2(x+3) miles away from the starting point
(2x)^2+(2(x+3))^2=900
4x^2+(2x+6)^2=900
4x^2+4x^2+24x+36=900
8x^2+24x-864=0
/8
x^2+3x-108=0
x^2+12x-9x-108=0
x(x+12)-9(x+12)=0
(x+12)(x-9)=0
take the postive value
x= 9 mph the speed of south bound
12mph east bound