Based on the given diagram, we can determine the factors by adding up the terms in the topmost row and in the leftmost column. The topmost row has +x+x+1+1+1 = 2x+3, while the leftmost column has +x+1 = x+1. Therefore, the factorization of this is (2x+3)(x+1).
You can double-check by multiplying the factors to find that 2x^2 + 2x + 3x + 3 = 2x^2 + 5x + 3, which is the original expression.