Answer
$x^{2}-x+2$
Work Step by Step
First, distribute the sign located between the two polynomials to the second polynomial. Since it is a positive, none of the signs will change. After distribution, it will remain the same: $$(5x^{2}-4x+7)+(-4x^{2}+3x-5)$$ . After distribution, the parenthesis can be dropped so that you are left with: $$5x^{2}-4x+7-4x^{2}+3x-5$$ Then simply combine like terms. The squareds with the squareds, etc. $$x^{2}-x+2$$
