Given expression is (3x² + 2x + 1)(5x + 4)
Multiply each term of the first polynomial with every term of the second polynomial.
(3x² + 2x + 1)(5x + 4) = 3x²(5x + 4) + 2x(5x + 4) + 1(5x + 4)
= 15x³ + 12x² + 10x² + 8x + 5x + 4
= 15x³ + 22x² + 13x + 4