Respuesta :
A) (S * H ) / (S + H) = 60
B) 2*H = S
Inserting "B" into "A"
(2H * H) / (2H + H) = 60
2H^2 = 120H + 60H
2H^2 -180 H = 0
H = 90 minutes
S = 180 minutes
Double Check
(180 * 90 ) / (180 + 90) = 60
Correct
Hilda takes 90 minutes Stan takes 180 minutes.
B) 2*H = S
Inserting "B" into "A"
(2H * H) / (2H + H) = 60
2H^2 = 120H + 60H
2H^2 -180 H = 0
H = 90 minutes
S = 180 minutes
Double Check
(180 * 90 ) / (180 + 90) = 60
Correct
Hilda takes 90 minutes Stan takes 180 minutes.