1 times 8 is 8, but what is the answer if both 1 and 8 are negative numbers? Here we will determine if the answer to negative 1 times negative 8 is positive 8 or negative 8.
There are many different ways to explain and determine if the answer to negative 1 times negative 8 is -8 or +8 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 -8 is the correct answer using basic algebra.
We will test if -8 is correct by setting up the equation negative 1 times negative 8 equals negative 8, and then simplifying the equation to see if it is true.
(-1) (-8) = (-8)
Divide both sides of the equation by (-8) :
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| = |
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The numerator and denominator on the left side both have (-8) which even each other out and can be removed:
| (-1) = |
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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:
| (-1) = |
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A numerator of 8 and denominator of 8 on the right side is the same as 8 divided by 8 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 8 is not equal to -8. The answer must therefore be 8:
-1 x -8 = 8
The above applies to all math problems where you multiply two negative numbers. Multiplying two negative numbers such as negative 1 times negative 8 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 9?
Here is the next problem on our list that we have explained and calculated.
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