<PRE><B>Question 243390</B>
1) X-Y=40
X+Y=48 ADD
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2X=88
X=88/2
X=44 ANS.
44-Y=40
Y=44-40
Y=4 ANS.
PROOF:
44+4=48
48=48
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2) 6X-12=X+13
6X-X=13+12
5X=25
X=25/5
X=5 ANS.
PROOF:
6*5-12=5+13
30-12=18
18=18
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3) X-Y=5 OR X=Y+5
(X+5)+12=2(Y-8)
Y+5+5+12=2Y-16
Y-2Y=-16-5-5-12
-Y=-38
Y=38 ANS.
X-38=5
X=5+38
X=43 ANS.
PROOF:
43+5+12=2(38-8)
60=2*30
60=60
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