Square DEFG with vertices D(0, 0), E(2, 4), F(6,2), and G(4, -2): k = 5/2.

If the scale factor between two circles is 2x/5y what is the ratio of their areas?

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?

Can someone explain to me how to do