3. The graph of part of linear function h is shown on the grid. (a) Write an inequality to represent the domain of the part shown. Explain your answer.
(b) Write an inequality to represent the range of the part shown. Explain your answer.

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?