Chapter 10 - Exponents and Radicals - 10.8 The Complex Numbers - 10.8 Exercise Set - Page 686: 31

$2-i$

Removing the grouping symbols and then adding the real parts and the imaginary parts, the given expression, $ (7-4i)-(5-3i) ,$ simplifies to \begin{array}{l}\require{cancel} 7-4i-5+3i \\\\= (7-5)+(-4i+3i) \\\\= 2-i .\end{array}