77 times 31 is 2387, but what is the answer if both 77 and 31 are negative numbers? Here we will determine if the answer to negative 77 times negative 31 is positive 2387 or negative 2387.
There are many different ways to explain and determine if the answer to negative 77 times negative 31 is -2387 or +2387 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 -2387 is the correct answer using basic algebra.
We will test if -2387 is correct by setting up the equation negative 77 times negative 31 equals negative 2387, and then simplifying the equation to see if it is true.
(-77) (-31) = (-2387)
Divide both sides of the equation by (-31) :
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| = |
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The numerator and denominator on the left side both have (-31) which even each other out and can be removed:
| (-77) = |
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The numerator and denominator on the right side both have a minus sign (-) which even each other out and can be removed:
| (-77) = |
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A numerator of 2387 and denominator of 31 on the right side is the same as 2387 divided by 31 which is 77. Now we end up with this untrue equation:
(-77) = (77)
-77 is NOT equal to 77, thus we have proven that negative 77 times negative 31 is not equal to -2387. The answer must therefore be 2387:
-77 x -31 = 2387
The above applies to all math problems where you multiply two negative numbers. Multiplying two negative numbers such as negative 77 times negative 31 will always have a positive answer.
Negative Times Negative Calculator
Here you can multiply another two negative numbers together.
What is negative 77 times negative 32?
Here is the next problem on our list that we have explained and calculated.
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