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Answer:
A + B = -50
A - B = 10
Explanation:
A + B
(-20) + (-30)
= -50
A - B
(-20) - (-30)
= 10
a+b=-30 and a-b=10
a= -20
b= -30
a+b
-20+(-30)
-20-30
-50
a-b
-20-(-30)
-20+30
10
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