3 times 28 is 84, but what is the answer if both 3 and 28 are negative numbers? Here we will determine if the answer to negative 3 times negative 28 is positive 84 or negative 84.
There are many different ways to explain and determine if the answer to negative 3 times negative 28 is -84 or +84 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 -84 is the correct answer using basic algebra.
We will test if -84 is correct by setting up the equation negative 3 times negative 28 equals negative 84, and then simplifying the equation to see if it is true.
(-3) (-28) = (-84)
Divide both sides of the equation by (-28) :
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| = |
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The numerator and denominator on the left side both have (-28) which even each other out and can be removed:
| (-3) = |
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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:
| (-3) = |
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A numerator of 84 and denominator of 28 on the right side is the same as 84 divided by 28 which is 3. Now we end up with this untrue equation:
(-3) = (3)
-3 is NOT equal to 3, thus we have proven that negative 3 times negative 28 is not equal to -84. The answer must therefore be 84:
-3 x -28 = 84
The above applies to all math problems where you multiply two negative numbers. Multiplying two negative numbers such as negative 3 times negative 28 will always have a positive answer.
Negative Times Negative Calculator
Here you can multiply another two negative numbers together.
What is negative 3 times negative 29?
Here is the next problem on our list that we have explained and calculated.
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