What is negative 5 times negative 42? (-5 x -42)

What is negative 5 times negative 42?

5 times 42 is 210, but what is the answer if both 5 and 42 are negative numbers? Here we will determine if the answer to negative 5 times negative 42 is positive 210 or negative 210.

There are many different ways to explain and determine if the answer to negative 5 times negative 42 is -210 or +210 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 -210 is the correct answer using basic algebra.

We will test if -210 is correct by setting up the equation negative 5 times negative 42 equals negative 210, and then simplifying the equation to see if it is true.

(-5) (-42) = (-210)

Divide both sides of the equation by (-42) :

		(-5) (-42)
		(-42)

		(-210)
		(-42)

The numerator and denominator on the left side both have (-42) which even each other out and can be removed:

(-5) =

		(-210)
		(-42)

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

(-5) =

		(210)
		(42)

A numerator of 210 and denominator of 42 on the right side is the same as 210 divided by 42 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 42 is not equal to -210. The answer must therefore be 210:

-5 x -42 = 210

The above applies to all math problems where you multiply two negative numbers. Multiplying two negative numbers such as negative 5 times negative 42 will always have a positive answer.

Negative Times Negative Calculator
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