## Intermediate Algebra (6th Edition)

$2x(2x-1)$
The two numbers whose product is $ac= 1(2)=2$ and whose sum is $b= -3$ are $\{ -1,-2 \}$. Using these two numbers to decompose the middle term of the given expression, $(2x+1)^2-3(2x+1)+2$, results to \begin{array}{l} (2x+1)^2-2(2x+1)-1(2x+1)+2 \\\\= [(2x+1)^2-2(2x+1)]-[1(2x+1)-2] \\\\= (2x+1)[(2x+1)-2]-[(2x+1)-2] \\\\= [(2x+1)-2][(2x+1)-1] \\\\= (2x+1-2)(2x+1-1) \\\\= (2x-1)(2x) \\\\= 2x(2x-1) .\end{array}