Step 3 in factoring by grouping: factor out the common binomial.
A diagram illustrating the process of factoring a polynomial by grouping, showing the expression (3x² + 2x) + (12x + 8) being factored into x(3x + 2) + 4(3x + 2), then into (x + 4)(3x + 2), with colorful blocks and arrows indicating the steps.