3 times 90 is 270, but what is the answer if both 3 and 90 are negative numbers? Here we will determine if the answer to negative 3 times negative 90 is positive 270 or negative 270.
There are many different ways to explain and determine if the answer to negative 3 times negative 90 is -270 or +270 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 -270 is the correct answer using basic algebra.
We will test if -270 is correct by setting up the equation negative 3 times negative 90 equals negative 270, and then simplifying the equation to see if it is true.
(-3) (-90) = (-270)
Divide both sides of the equation by (-90) :
|
| = |
|
The numerator and denominator on the left side both have (-90) which even each other out and can be removed:
| (-3) = |
|
The numerator and denominator on the right side both have a minus sign (-) which even each other out and can be removed:
| (-3) = |
|
A numerator of 270 and denominator of 90 on the right side is the same as 270 divided by 90 which is 3. Now we end up with this untrue equation:
(-3) = (3)
-3 is NOT equal to 3, thus we have proven that negative 3 times negative 90 is not equal to -270. The answer must therefore be 270:
-3 x -90 = 270
The above applies to all math problems where you multiply two negative numbers. Multiplying two negative numbers such as negative 3 times negative 90 will always have a positive answer.
Negative Times Negative Calculator
Here you can multiply another two negative numbers together.
What is negative 3 times negative 91?
Here is the next problem on our list that we have explained and calculated.
Copyright | Privacy Policy | Disclaimer | Contact