Asystem of equations has 1 solution. if 4x-y=5 is one of the equations which could be the other equations

Noor brought 21 sheets of stickers. she gave 1/3 of a sheet to each of the 45 students at recess. she wants to give teachers 1 1/2 sheets each.

The estimated number of people to attend the last bengals game of the season was 2000. the actual number of fans attending was 1200. by what percent did the estimate differ from the actual?

What is x3+3x2−16x−48 divided by x−1?