Identify each as exponential growth or decay. Identify both the A and B value of each function.
1. y=5*(1/2)^x 2.y=5.2^x
3. y=2*(1/2)^x 4. y=2*2^x

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?