Cindy has 6 identical pink candies and 8 identical green candies. Find the number of ways that Cindy can line up her candies in a row, so that there are exactly four places where a pink candy is next to a green candy.

What number should be added to both sides of the equation to complete this square? x^2-10x=7

With finding limits of multi variable !

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?