Need help!! I don't know how to solve these.

Rectangle pqrs has length a and width 4b. the x-axis bisects ps and qr what are the coordinates of the vertices

Complete the solution of the equation. find the value of y when x equals to 6 4x+y=20

An automobile assembly line operation has a scheduled mean completion time, μ, of 12 minutes. the standard deviation of completion times is 1.6 minutes. it is claimed that, under new management, the mean completion time has decreased. to test this claim, a random sample of 33 completion times under new management was taken. the sample had a mean of 11.2 minutes. assume that the population is normally distributed. can we support, at the 0.05 level of significance, the claim that the mean completion time has decreased under new management? assume that the standard deviation of completion times has not changed.