Let a, b,,c and x elements in the group g. in each of the following solve for x in terms of a, b,c, and c.
solve simultaneously x^2 a=bxc^-1 and acx=xac.

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. how many hours after the truck's departure will the two meet?