Solve the following system of equations 9x +2y=17

If i have a 24 in loaf of bread and i cut it into two pieces one 9 in how long was the other

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?

Need asap. solve for the following inequality