Write the product in descending powers of x. (x2 + 3x + 1) (x2 + x + 2)

Multiply each term in one bracket by each in the other:

(I assume x2 means x^2 / x squared)

(x^2 + 3x + 1) (x^2 + x + 2)

= x^4 + x^3 + 2x^2 + 3x^3 + 3x^2 + 6x + x^2 + x + 2

Now collect all terms:

= x^4 + 4x^3 + 6x^2 + 7x + 2