Signed Numbers (Positive and Negative) - Examples, Exercises and Solutions

To determine the sign of the expression $(-16)\cdot(-5)$, we follow these logical steps:

• Step 1: Identify the signs of the numbers involved. Both numbers $(-16)$ and $(-5)$ are negative.
• Step 2: Apply the rule for multiplication of signed numbers: The product of two numbers with the same sign (both negative) is always positive.

Therefore, the sign of the result for the expression $(-16)\cdot(-5)$ is Positive.

It's important to remember: when we multiply a negative by a negative, the result is positive!

You can use this guide:

Let's remember the rule:

$(-x)\times(-x)=+x$

Therefore, the sign of the exercise result will be positive:

$-3\times-4=+12$

Let's recall the law:

$(-x)\times(-x)=+x$

Therefore, the sign of the exercise result will be positive:

$-2\times-\frac{1}{2}=+1$

When there is no minus or plus sign before the numbers, we usually assume that these are positive numbers as shown below:

(+1/4)*(+1/2)=

The dot in the middle represents multiplication:

So the question in other words is - what happens when we multiply two positive numbers together?

We know that two positive integers when multiplied result in a positive integer:

Therefore the answer is "positive".