Lesson

Factorization by Grouping

When an expression has four terms, we often group terms in pairs and factor each pair. For example, x³ + x² + 3x + 3 can be grouped as (x³ + x²) + (3x + 3) and written as x²(x + 1) + 3(x + 1), which leads to (x² + 3)(x + 1). Grouping helps when no common factor exists across all terms.