78 times 47 is 3666, but what is the answer if both 78 and 47 are negative numbers? Here we will determine if the answer to negative 78 times negative 47 is positive 3666 or negative 3666.
There are many different ways to explain and determine if the answer to negative 78 times negative 47 is -3666 or +3666 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 -3666 is the correct answer using basic algebra.
We will test if -3666 is correct by setting up the equation negative 78 times negative 47 equals negative 3666, and then simplifying the equation to see if it is true.
(-78) (-47) = (-3666)
Divide both sides of the equation by (-47) :
|
| = |
|
The numerator and denominator on the left side both have (-47) which even each other out and can be removed:
| (-78) = |
|
The numerator and denominator on the right side both have a minus sign (-) which even each other out and can be removed:
| (-78) = |
|
A numerator of 3666 and denominator of 47 on the right side is the same as 3666 divided by 47 which is 78. Now we end up with this untrue equation:
(-78) = (78)
-78 is NOT equal to 78, thus we have proven that negative 78 times negative 47 is not equal to -3666. The answer must therefore be 3666:
-78 x -47 = 3666
The above applies to all math problems where you multiply two negative numbers. Multiplying two negative numbers such as negative 78 times negative 47 will always have a positive answer.
Negative Times Negative Calculator
Here you can multiply another two negative numbers together.
What is negative 78 times negative 48?
Here is the next problem on our list that we have explained and calculated.
Copyright | Privacy Policy | Disclaimer | Contact