Tomas factored the polynomial completely. what is the value of c?

3x4 – 18x3 + 9x2 –54x
ax(x2 + b) (x + c)

If the ratio of sum of the first m and n terms of an ap is m2 : n2 , show that the ratio of its mth and nth terms is (2m − 1) : (2n − 1).

Each person in an it department of 25 people works on at least one of 3 major projects: system security, program implementation, platform development. 10 people work on system security, 13 work on program implementation, and 12 work on platform development. 4 people work on system security and platform development, 5 people work on program implementation and platform development, and 2 people work on all three projects. how many people work on system security and program implementation?

What is the name of a polygon that has four congruent sides and theses angle measures 60,120,60,120?