<PRE><B>Question 212175</B>
A+B+C+D=9,900 OR D=9,900-(A+B+C)
B=A+A/7 
C=(A+B)+300
 
D=(A+B+C)+300 
D=-(A+B+C)+9,900 NOW ADD.
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2D=300+9,900
2D=10,200
D=10,200/2
D=5,100 ANS.
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C=A+B+300
-[5,100=A+B+C+300] SUBTRACT
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C-5,100=-C
2C=5,100
2C=5,100
C=5,100/2
C=2,550 ANS.
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B=A+A/7 
C=(A+B)+300 OR C=(A+A+A/7)+300 OR C=(7A+7A+A)/7+300 OR C=15A/7+300
2,550=15A/7+300
15A/7=2,550-300
15A/7=2,250
15A=2,250*7
15A=15,750
A=15,750/15
A=1,050 ANS
B=1,050+1,050/7
B=(7*1,050+1,050)/7
B=(7,350+1,050)/7)
B=8,400/7
B=1,200
PROOF:
1,050+1,200+2,550+5,100=9,900</PRE>