What is the coefficient of x^2 in (x^3 + x^2 + x + 1)(x^4 + 3x^3 + 8x + 7x + 1)?
(x^3 + x^2 + x + 1)(x^4 + 3x^3 + 8x + 7x + 1)
"x^2" terms occur with the multiplications of
x^2 * 1 + x *7x + x * 8x =
x^2 + 7x^2 + 8x^2 =
16x^2