(9x + 4) * 2x^2
1. Regroup the terms.
2x^2(9x + 4)
2. Expand by distributing the terms.
2x^2 * 9x + 2x^2 * 4
3. Take out the constants.
(2 * 9)x^2x + 2x^2 * 4
4. Simplify 2 * 9 to 18.
18x^2x + 2x^2 * 4
5. Use this product rule: x^ax^b = x^a+b.
18x^2+1 + 2x^2 * 4
6. Simplify 2 + 1 to 3.
18x^3 + 2x^2 * 4
7. Simplify 2x^2 * 4 to 8x^2.
18x^3 + 8x^2
Therefore your answer is:
18x^3 + 8x^2
