1 times 5 is 5, but what is the answer if both 1 and 5 are negative numbers? Here we will determine if the answer to negative 1 times negative 5 is positive 5 or negative 5.
There are many different ways to explain and determine if the answer to negative 1 times negative 5 is -5 or +5 using mathematical terms such as additive inverse and mathematical laws like the Distribute Law.
We will take a different approach - process of elimination: We will simply test if -5 is the correct answer using basic algebra.
We will test if -5 is correct by setting up the equation negative 1 times negative 5 equals negative 5, and then simplifying the equation to see if it is true.
(-1) (-5) = (-5)
Divide both sides of the equation by (-5) :
|
| = |
|
The numerator and denominator on the left side both have (-5) which even each other out and can be removed:
| (-1) = |
|
The numerator and denominator on the right side both have a minus sign (-) which even each other out and can be removed:
| (-1) = |
|
A numerator of 5 and denominator of 5 on the right side is the same as 5 divided by 5 which is 1. Now we end up with this untrue equation:
(-1) = (1)
-1 is NOT equal to 1, thus we have proven that negative 1 times negative 5 is not equal to -5. The answer must therefore be 5:
-1 x -5 = 5
The above applies to all math problems where you multiply two negative numbers. Multiplying two negative numbers such as negative 1 times negative 5 will always have a positive answer.
Negative Times Negative Calculator
Here you can multiply another two negative numbers together.
What is negative 1 times negative 6?
Here is the next problem on our list that we have explained and calculated.
Copyright | Privacy Policy | Disclaimer | Contact