## Elementary Algebra

We will evaluate the expression by first simplifying the expression and then substituting $x=-1$ into the resultant expression: $(x^{2}+2x-4)-(x^{2}-x-2)+(2x^{2}-3x-1)$ =$x^{2}+2x-4-x^{2}+x+2+2x^{2}-3x-1$ =$x^{2}-x^{2}+2x^{2}+2x+x-3x-1-4+2$ =$2x^{2}+3x-3x-5+2$ =$2x^{2}+0-3$ =$2x^{2}-3$ =$2(-1)^{2}-3$ =$2(1)-3$ =$2-3$ =$-1$