Cuanto es esto con explicación :3x-12=9x_30

Acyclist bike x distance at 10 miles per hour .and returns over the same path at 8 miles per hour.what is the cyclist average rate for the round trip in miles per hour ?

If f(x) = 3x2 - 2x+4 and g(x) = 5x + 6x - 8, find (f-g)(x).

Which of these could you find on a credit report? check all that apply. previous address current employer highest level of education completed bankruptcy and a civil court case monthly income late credit card payments