A hovercraft takes off from a platform. It’s height(in meters), x seconds after takeoff, is modeled by h(x)=-(x-11)(x+3) how many seconds after takeoff will the hovercraft land on the ground?

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?