Question 983873
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x=9-3y
x-9=-3y
9-x=3y
(9-x)/3=y
3-(x/3)=y
ANSWER: y=3-(x/3)
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For x=-3:
y=3-(-3/3)=3+1=4 
ANSWER:(-3,4)
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For x=6:
y=3-(6/3)=3-2=1
ANSWER: (6,1)
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Try the last one on your own.