SOLUTION: Bicyclists Mia and Pia leave the same point P at the same time at right angles. Pia travels 7 km/h faster than Mia. After three hours, they are 39 km apart. Find the speed of each

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: Bicyclists Mia and Pia leave the same point P at the same time at right angles. Pia travels 7 km/h faster than Mia. After three hours, they are 39 km apart. Find the speed of each       Log On


   

Question 1086844: Bicyclists Mia and Pia leave the same point P at the same time at right angles. Pia travels 7 km/h faster than Mia. After three hours, they are 39 km apart. Find the speed of each cyclist.
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Rate x Time = Distance,
P=M%2B7
D%5BP%5D=%28M%2B7%293=3M%2B21
D%5BM%5D=M%283%29=3M
and
D%5BP%5D%5E2%2BD%5BM%5D%5E2=39%5E2
Substituting,
%283M%2B21%29%5E2%2B%283M%29%5E2=1521
9M%5E2%2B126M%2B441%2B9M%5E2=1521
18M%5E2%2B126M-1080=0
M%5E2%2B7M-60=0
%28M%2B12%29%28M-5%29=0
Only positive rates make sense here,
M-5=0
M=5kph
and
P=5%2B7
P=12kph