A child and sled with a combined mass of 53.8 kg slide down a frictionless hill that is 11.5 m high at an angle of 25° from horizontal. The acceleration of gravity is 9.81 m/s. If the sled starts from rest, what is its speed at the bottom of the hill?

If its history of, then b) because a) implies only present day (now)

Make them both to where they have the denominator of 18that makes 3/2 equal 27/18 and 1/9 equal 2/18so now you have  27/18x+5=2/18subtract 5 from the other sideso now you have 27/18x+2/18-5then subtract 2/18 from 27/18 to get 25/18x=-5then divide 25/18 by -5 and your answer will be  -5/18