Multiply each term in the first set of parentheses by each term in the second set, then combine like terms.
7x x 3x^2 = 21x^3
7x x -4x = -28x^2
7x x 5 + 35x
-6 x 3x^2 = -18x ^2
-6 x -4x = 24x
-6 x 5 = -30
Combine like terms to get:
21x^3 - 46x^2 + 59x - 30
