Let’s solve each part step by step.
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a) (-16) – (2)
Subtracting a positive is like adding a negative:
-16 + (-2) = -18
✔ Final:
-18
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b) (-20) + (-30)
Adding two negatives: add their absolute values and keep the negative sign.
20 + 30 = 50 → so answer is -50
✔ Final:
-50
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c) 9 + (-9) + 5
9 + (-9) = 0, then 0 + 5 = 5
✔ Final:
5
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d) (-34) – (-6)
Subtracting a negative is like adding:
-34 + 6 = -28
✔ Final:
-28
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e) (-12) – 7
This is -12 + (-7) = -19
✔ Final:
-19
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f) 70 + 12 – (-32)
First, 70 + 12 = 82
Then, subtracting -32 is like adding 32: 82 + 32 = 114
✔ Final:
114
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g) (-56) + 78
Think of it as 78 – 56 = 22 (since 78 is bigger and positive)
✔ Final:
22
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h) (-3) – (-4)
Subtracting -4 is like adding 4: -3 + 4 = 1
✔ Final:
1
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i) 8 + (-4) + (-12)
8 + (-4) = 4; then 4 + (-12) = -8
✔ Final:
-8
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j) (-13) + (4)
Start at -13, go up 4: -13 + 4 = -9
✔ Final:
-9
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k) -45 – (-45)
Subtracting -45 is like adding 45: -45 + 45 = 0
✔ Final:
0
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L) 6 + (-8) + (-3)
6 + (-8) = -2; then -2 + (-3) = -5
✔ Final:
-5
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M) Temperature problem
At 6:00 pm: 87°C
By 10:00 pm, temperature decreased by 12°C → that means we subtract 12.
Expression:
87 – 12
Solution: 87 – 12 = 75
✔ Expression:
87 – 12
✔ Solution:
75
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Final Answer:
a) -18
b) -50
c) 5
d) -28
e) -19
f) 114
g) 22
h) 1
i) -8
j) -9
k) 0
L) -5
M) Expression: 87 – 12, Solution: 75
Parent Tip: Review the logic above to help your child master the concept of 9th grade subtraction worksheet.
