Q. 1.35 - An Introduction to General, Organic, and Biological Chemistry

Question

For each of the following, indicate if the answer has a positive or negative sign:$\left(1.4\right)$
 a. Two negative numbers are added.
 b. A positive and negative number are multiplied.

Step-by-Step Solution

Answer

a. The sign will be negative when two negative numbers are added.

b.  The sign will be negative when a positive and negative number are multiplied. 

Part (a) step 1: Given Information

We need to find the sign when two negative numbers are added. 

Part (a) step 2: Explanation

When we add two negative numbers always results to a negative number, as exemplified by some examples: $\left(-3\right)+\left(-5\right)=-8$ and $\left(-0.1\right)+\left(-4\right)=-4.1$.

Part (b) step 1: Given Information

We need to find sign when a positive and negative numbers are multiplied.

Part (b) step 2: Explanation

Any two numbers with opposing sign always yield a negative number. For examples: $\left(-2\right)\times \left(17\right)=-34$ and $\left(5\right)\times \left(-0.2\right)=-1$.