Chapter 5 - Exponents and Polynomials - 5.1 - Addition and Subtraction of Polynomials - Problem Set 5.1 - Page 195: 52

$-2x+2$

By using the distributive property, removing the grouping symbols, and then combining like terms, the given expression, $ (3x-4)+(9x-1)-(14x-7) ,$ simplifies to \begin{array}{l}\require{cancel} 3x-4+9x-1-14x+7 \\\\= (3x+9x-14x)+(-4-1+7) \\\\= -2x+2 .\end{array}