Is 3/4 equivalent to 9/12 plz tell me i need

What expression is equivalent to 1/2(2+3x-6)

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 solution(s) to x^2-14+49=0