Chapter 5 - Exponents and Polynomials - 5.1 - Addition and Subtraction of Polynomials - Problem Set 5.1 - Page 195: 53

$-3x-14$

By using the distributive property, removing the grouping symbols, and then combining like terms, the given expression, $ (-x-1)-(-2x+6)+(-4x-7) ,$ simplifies to \begin{array}{l}\require{cancel} -x-1+2x-6-4x-7 \\\\= (-x+2x-4x)+(-1-6-7) \\\\= -3x-14 .\end{array}