Identify the property 16m=160 then m=10

What properties allow transformation to be used as a problem solving tool

The table shows the balance of a money market account over time. write a function that represents the balance y(in dollars) after t years.

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?