What is negative 7 times negative 20? (-7 x -20)

What is negative 7 times negative 20?

7 times 20 is 140, but what is the answer if both 7 and 20 are negative numbers? Here we will determine if the answer to negative 7 times negative 20 is positive 140 or negative 140.

There are many different ways to explain and determine if the answer to negative 7 times negative 20 is -140 or +140 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 -140 is the correct answer using basic algebra.

We will test if -140 is correct by setting up the equation negative 7 times negative 20 equals negative 140, and then simplifying the equation to see if it is true.

(-7) (-20) = (-140)

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

		(-7) (-20)
		(-20)

		(-140)
		(-20)

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

(-7) =

		(-140)
		(-20)

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

(-7) =

		(140)
		(20)

A numerator of 140 and denominator of 20 on the right side is the same as 140 divided by 20 which is 7. Now we end up with this untrue equation:

(-7) = (7)

-7 is NOT equal to 7, thus we have proven that negative 7 times negative 20 is not equal to -140. The answer must therefore be 140:

-7 x -20 = 140

The above applies to all math problems where you multiply two negative numbers. Multiplying two negative numbers such as negative 7 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 7 times negative 21?
Here is the next problem on our list that we have explained and calculated.