How long is the red ribbon if the blue ribbon is x inches?

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?

Grant simplified the expression 1.5(-3.2 + 2.5) his work is shown below explain the error in grants work

Whoever gets this right gets the ! the half life of a soul smelling substance is 4 years. if you have 8 oz of this strange substance, how much of it will you have after 20 years? show work.