Someone plz asap will mark brainliest and worth 25 points

Pick the description of a geometric object that best matches the real world object box for a deck of card

If f(x)=-x^2+6x-1 and g(x)=3x^2-4x-1,find(f+g)(x)

Is the product of two rational numbers irrational or rational? first, make a hypothesis by multiplying two rational numbers. then, use variables such as x=a/b and y=c/d and the closure property of integers to prove your hypothesis.