Can someone me with this question?

What value of x is in the solution set of 4x - 12 s 16 + 8x? -10 -9 -8 -7

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?

Find the value of x for which line a is parallel to line b