Here you go all of those nice people out there

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?

Give the functions f(x) = |x + 2| - 3, what is the domain? a,b,c, or d all real numbers x > 2 x < -2 all real numbers and x cannot equal to 2

Round each of the decimals to the nearest hundredth a. 0.596 b. 4.245 c. 53.6843 d. 17.999