Question 848229
Let x be the speed at which the bus is travelling. Let y be the time in which it took for the truck to travel the 560km.

distance = rate * time

(bus)  560 = x km/h  * y+1 hours

(truck) 560 = (x+10) * y

560 = xy + x
560 = xy + 10y

xy+x = xy+10y

x = 10y


560 = 10y^2 + 10y

56 = y^2 + y

y^2 +y - 56 = 0

(y-7)(y+8) = 0

y = 7   (can't have y=-8)

x = 70

So the bus traveled 70 km/h.

And it took the truck 7 hours to travel the 560km.