07.03.2007, 16:49
X/t=4,9km/h
X/t+25min=4,2km/h
a:
X=4,9km/h*t=4,2km/h*(t+25min)
t=4,2km/4,9km*(t+25min)
t=42/49*t+42/49*25min | *49
49t=42t+42*25min |-42t
7t=42*25min |/7
t=6*25min=150min=2,5h
b:
X/2,5h=4,9km/h |*2,5h
X=2,5*4,9km
X=12,25km
X/t+25min=4,2km/h
a:
X=4,9km/h*t=4,2km/h*(t+25min)
t=4,2km/4,9km*(t+25min)
t=42/49*t+42/49*25min | *49
49t=42t+42*25min |-42t
7t=42*25min |/7
t=6*25min=150min=2,5h
b:
X/2,5h=4,9km/h |*2,5h
X=2,5*4,9km
X=12,25km