7 times 91 is 637, but what is the answer if both 7 and 91 are negative numbers? Here we will determine if the answer to negative 7 times negative 91 is positive 637 or negative 637.
There are many different ways to explain and determine if the answer to negative 7 times negative 91 is -637 or +637 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 -637 is the correct answer using basic algebra.
We will test if -637 is correct by setting up the equation negative 7 times negative 91 equals negative 637, and then simplifying the equation to see if it is true.
(-7) (-91) = (-637)
Divide both sides of the equation by (-91) :
|
| = |
|
The numerator and denominator on the left side both have (-91) which even each other out and can be removed:
| (-7) = |
|
The numerator and denominator on the right side both have a minus sign (-) which even each other out and can be removed:
| (-7) = |
|
A numerator of 637 and denominator of 91 on the right side is the same as 637 divided by 91 which is 7. Now we end up with this untrue equation:
(-7) = (7)
-7 is NOT equal to 7, thus we have proven that negative 7 times negative 91 is not equal to -637. The answer must therefore be 637:
-7 x -91 = 637
The above applies to all math problems where you multiply two negative numbers. Multiplying two negative numbers such as negative 7 times negative 91 will always have a positive answer.
Negative Times Negative Calculator
Here you can multiply another two negative numbers together.
What is negative 7 times negative 92?
Here is the next problem on our list that we have explained and calculated.
Copyright | Privacy Policy | Disclaimer | Contact