Ignore the shimejis. also if there is a calculator for this type of thing tell me

What is f(3) for the quadratic functionf(x)=2x2 + x – 12? f -3g 3h 6i. 9

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 area of the shaded sector?