Math A

Subtracting
 Signed Numbers

 

Rule:   You can subtract a number by
adding its opposite.

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Examples:      Subtract :
 
1.   9 – (- 3) = 5. -10 - (-15) =
9 + (+3) = 12 -10 + (+15) = 5
 

2.

 -7 – (-5) =   6. -25 - (+25) =
-7 + (+5) = -2 -25 + (-25) = -50
 

3.

 21 – (-19) =      7. 3 - (+5) =
21 + (+19) = 40 3 + (-5) = -2
 

4. 

 - 5 - 4 =      8. 9 - 3 =
- 5 + (-4) = -9 9 + (-3) = 6

 

9.   Subtract (-5) from (10).
       10 - (-5) = 10 + (+5) = 15

 

10.   Subtract 4 from (-14).
      -14 - 4 = -14 + (-4) = -18

 

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Roberts

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