2x^3 (7x^2 + 3x + 1) - 4x^4
multiply 2x^3 in
14x^5 + 6x^4 + 2x^3 - 4x^4
14x^5 + 2x^4 + 2x^3
3 terms, the degree is 5
terms are single expressions such as (2x^3)
the degree is the highest exponent
(6x - 2x^4 + 5x^6) + (7x^4 - 3x^6 + 9)
combine
6x - 2x^4 + 5x^6 + 7x^4 - 3x^6 + 9
simplify
2x^6 + 5x^4 + 6x + 9
4 terms, the degree is 6
(x^2 + 9)(x^2 - 9)
FOIL, (a + b)(c + d) -> ac + ad + bc + bd
x^2 * x^2 + x^2 * -9 + 9 * x^2 + 9 * -9
simplify
x^4 - 81
2 terms, the degree is 4