## Intermediate Algebra (12th Edition)

$2x^2+5x+4$
$\bf{\text{Solution Outline:}}$ Combine like terms to simplify the given expression, $3x^2-4x+4+9x-x^2 .$ $\bf{\text{Solution Details:}}$ By combining like terms, the expression above is equivalent to \begin{array}{l}\require{cancel} (3x^2-x^2)+(-4x+9x)+4 \\\\= 2x^2+5x+4 .\end{array}