Chapter 5 - Exponents and Polynomials - 5.1 - Addition and Subtraction of Polynomials - Problem Set 5.1 - Page 195: 51

$x+11$

By using the distributive property, removing the grouping symbols, and then combining like terms, the given expression, $ (5x+3)-(7x-2)+(3x+6) ,$ simplifies to \begin{array}{l}\require{cancel} 5x+3-7x+2+3x+6 \\\\= (5x-7x+3x)+(3+2+6) \\\\= x+11 .\end{array}