Omar grouped the terms and factored the GCF out of the groups of the polynomial 3x3 – 15x2 – 4x + 20. His work is shown.
Step 1: (3x3 – 15x2) + (–4x + 20)
Step 2: 3x2(x – 5) + 4(–x + 5)
Omar noticed that he does not have a common factor. Which accurately describes what Omar should do next?