Question

(x^2 + 3x + 1)(x^2 + x + 2)
I got: X^4+3X^4+2X^4 is that right?

Answer 1

no. you have to do this in steps. If we call (x^2 + 3x + 1) A
that is A= (x^2 + 3x + 1) (for ease of typing)
the problem is
A*(x^2 + x + 2)
distribute the A (multiply every term inside the parens by A)
now replace A with its "real" meaning: (x^2 + 3x + 1)
now distribute again
then "collect like terms" x^4 terms, x^3 terms, x^2 terms and so on