Let f(x) = 2x + 2. Solve f^−1(x) when x = 4. So do I substitute x for y and then how do I solve f^-1(x)???

(9x-5) - (x+12) what’s the answer and also explain how to do it i need it for a test tomorrow

Use the graph of the sine function y=2sinθ shown below

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?