If f (x) = x2 - 3x, what is the value of f (-2)? work it out.

What is the solution of the systems of equations? y=2/3x+3 x=-2

Which expression is equivalent to 8(k + m) − 15(2k + 5m)?

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?