Which ordered pairs is a solution for 3x-1=y?

An advertising firm has an old computer that can prepare a whole mailing in 6 hours. with the of newer model the job is complete in 2 hours. how long would it take the newer model to do the job alone?

Which shows the correct solution of the equation 1/2a+2/3b=50, when b=30?

Solve each equation using the quadratic formula. find the exact solutions. 6n^2 + 4n - 11