40 times 86 is 3440, but what is the answer if both 40 and 86 are negative numbers? Here we will determine if the answer to negative 40 times negative 86 is positive 3440 or negative 3440.
There are many different ways to explain and determine if the answer to negative 40 times negative 86 is -3440 or +3440 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 -3440 is the correct answer using basic algebra.
We will test if -3440 is correct by setting up the equation negative 40 times negative 86 equals negative 3440, and then simplifying the equation to see if it is true.
(-40) (-86) = (-3440)
Divide both sides of the equation by (-86) :
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| = |
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The numerator and denominator on the left side both have (-86) which even each other out and can be removed:
| (-40) = |
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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:
| (-40) = |
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A numerator of 3440 and denominator of 86 on the right side is the same as 3440 divided by 86 which is 40. Now we end up with this untrue equation:
(-40) = (40)
-40 is NOT equal to 40, thus we have proven that negative 40 times negative 86 is not equal to -3440. The answer must therefore be 3440:
-40 x -86 = 3440
The above applies to all math problems where you multiply two negative numbers. Multiplying two negative numbers such as negative 40 times negative 86 will always have a positive answer.
Negative Times Negative Calculator
Here you can multiply another two negative numbers together.
What is negative 40 times negative 87?
Here is the next problem on our list that we have explained and calculated.
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