Algebra-1

To factor the polynomial 3x³ + 8x² + 15x + 40 using the factor by grouping method, let's follow these steps:

Step 1: Group the terms: (3x³ + 8x²) + (15x + 40)

Step 2: Factor out the common factor from each group:
In the first group, we can factor out x²: x²(3x + 8).
In the second group, we can factor out 5: 5(3x + 8).

Now, we have: x²(3x + 8) + 5(3x + 8)