Chapter 1 - Introduction to Algebraic Expressions - 1.7 Multiplication and Division of Real Numbers - 1.7 Exercise Set - Page 58: 55

$-30,240$

The product of two numbers with opposite signs is negative while the product of two numbers with the same sign is positive. Multiplying the numbers from left-to-right, then the given expression, $ (-6)\cdot(-7)\cdot(-8)\cdot(-9)\cdot(-10) $, simplifies to \begin{array}{l} 42\cdot(-8)\cdot(-9)\cdot(-10) \\\\= -336\cdot(-9)\cdot(-10) \\\\= 3,024\cdot(-10) \\\\= -30,240 .\end{array}