Elementary Algebra

$-2n+6$
After using the distributive property, we first group like terms to ease simplification. We will then combine like terms to simplify the expression: $-(n-1)+2(n-2)-3(n-3)$ =$-n+1+2n-4-3n+9$ =$-n+2n-3n+1-4+9$ =$(-n+2n-3n)+(1-4+9)$ =$(-2n)+(6)$ =$-2n+6$