You are taking books from the library. There are 20 romance novels and 13 thrillers. You are picking three books and you want at least on of each genre. How many combinations of books are there?

I’m really confused and need to learn this

Four equations are shown below.equation 1: y=2*equation 2: y=2x-5equation 3: y=x2 + 6equation 4: tdentify one linear equation and one nonlinear equation from the list.why each equation you identified is linear or nonlinear.nd one nonlinear equation from the list. state a reasonlinear equation

Why is causation so much more difficult to prove than correlation?