SAT Math : How to subtract negative numbers

Study concepts, example questions & explanations for SAT Math

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Example Questions

Example Question #1 : Negative Numbers

If x is a negative integer, what else must be a negative integer?

 

Possible Answers:

x² – x

x – (–x)

x – x

Correct answer:

x – (–x)

Explanation:

By choosing a random negative number, for example: –4, we can input the number into each choice and see if we come out with another negative number.  When we put –4 in for x, we would have –4 – (–(–4)) or –4 – 4, which is –8.  Plugging in the other options gives a positive answer.  You can try other negative numbers, if needed, to confirm this still works. 

 

 

Example Question #2 : Negative Numbers

–7 – 7= x

–7 – (–7) = y

what are x and y, respectively

Possible Answers:

x = –14, y = 0

x = 0, y = 0

x = 14, y = –14

x = –14, y = 14

y = 0, x = 14

Correct answer:

x = –14, y = 0

Explanation:

x: –7 – 7= –7 + –7 = –14

y: –7 – (–7) = –7 + 7 = 0

when subtracting a negative number, turn it into an addition problem

Example Question #1 : Negative Numbers

Evaluate:  

Possible Answers:

Correct answer:

Explanation:

Reconvert  into single signs.  Remember that double negatives will turn into a positive.

Example Question #2 : Negative Numbers

Subtract:  

Possible Answers:

Correct answer:

Explanation:

Subtracting a negative number moves the number farther left of the zero digit on the number line. 

The answer is: 

Example Question #3 : Negative Numbers

Subtract:  

Possible Answers:

Correct answer:

Explanation:

Simplify the expression by eliminating the double negative signs.  Two negatives multiplied by one another will result in a positive number.

Convert the signs.

Add the right side of the equation.

The answer is .

Example Question #3 : Negative Numbers

Simplify the following expression:

Possible Answers:

Correct answer:

Explanation:

Simplify the following expression:

To subtract negative numbers, we must recall that subtracting negative numbers is the same as adding a positive. The two negatives cancel each other out to become positive.

So our answer is negative 220

 

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