65 times 8 is 520, but what is the answer if both 65 and 8 are negative numbers? Here we will determine if the answer to negative 65 times negative 8 is positive 520 or negative 520.
There are many different ways to explain and determine if the answer to negative 65 times negative 8 is -520 or +520 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 -520 is the correct answer using basic algebra.
We will test if -520 is correct by setting up the equation negative 65 times negative 8 equals negative 520, and then simplifying the equation to see if it is true.
(-65) (-8) = (-520)
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:
| (-65) = |
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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:
| (-65) = |
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A numerator of 520 and denominator of 8 on the right side is the same as 520 divided by 8 which is 65. Now we end up with this untrue equation:
(-65) = (65)
-65 is NOT equal to 65, thus we have proven that negative 65 times negative 8 is not equal to -520. The answer must therefore be 520:
-65 x -8 = 520
The above applies to all math problems where you multiply two negative numbers. Multiplying two negative numbers such as negative 65 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 65 times negative 9?
Here is the next problem on our list that we have explained and calculated.
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