What is negative 5 times negative 20? (-5 x -20)

What is negative 5 times negative 20?

5 times 20 is 100, but what is the answer if both 5 and 20 are negative numbers? Here we will determine if the answer to negative 5 times negative 20 is positive 100 or negative 100.

There are many different ways to explain and determine if the answer to negative 5 times negative 20 is -100 or +100 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 -100 is the correct answer using basic algebra.

We will test if -100 is correct by setting up the equation negative 5 times negative 20 equals negative 100, and then simplifying the equation to see if it is true.

(-5) (-20) = (-100)

Divide both sides of the equation by (-20) :

		(-5) (-20)
		(-20)

		(-100)
		(-20)

The numerator and denominator on the left side both have (-20) which even each other out and can be removed:

(-5) =

		(-100)
		(-20)

The numerator and denominator on the right side both have a minus sign (-) which even each other out and can be removed:

(-5) =

		(100)
		(20)

A numerator of 100 and denominator of 20 on the right side is the same as 100 divided by 20 which is 5. Now we end up with this untrue equation:

(-5) = (5)

-5 is NOT equal to 5, thus we have proven that negative 5 times negative 20 is not equal to -100. The answer must therefore be 100:

-5 x -20 = 100

The above applies to all math problems where you multiply two negative numbers. Multiplying two negative numbers such as negative 5 times negative 20 will always have a positive answer.

Negative Times Negative Calculator
Here you can multiply another two negative numbers together.

What is negative 5 times negative 21?
Here is the next problem on our list that we have explained and calculated.