Jul 18, 2009
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how to solve for y for this question,

y = (x+2)/(x-3).

and

AR-X, is it a meta or ortho/para director?

one of the question in the ADA sample test said it is para not meta, why?
 
May 15, 2009
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how to solve for y for this question,

y = (x+2)/(x-3).

and

AR-X, is it a meta or ortho/para director?

one of the question in the ADA sample test said it is para not meta, why?
Halogens are ring DEACTIVATORS that are Ortho/Para directors. Read any organic chemistry textbook and they will clearly explain why this is the case.
 
May 15, 2009
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thanks, can you also help me on the y=...
Are you sure they want you to solve for Y?
I look at this problem, and I see that Y is already solved for in terms of X. So, I'm not sure how to solve for Y, when Y is already equal to something in terms of X.
 
OP
P
Jul 18, 2009
16
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Are you sure they want you to solve for Y?
I look at this problem, and I see that Y is already solved for in terms of X. So, I'm not sure how to solve for Y, when Y is already equal to something in terms of X.
sorry, i mean x not y. my bad.
 

dentrilla

10+ Year Member
Aug 15, 2008
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Multiply both sides by (x-3) to get

yx-3y=x+2 (collect x's on one side to get...

yx-x=3y+2
x(y-1)=3y+2
x=(3y+2)/(y-1)
 
May 15, 2009
1,922
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how to solve for y for this question,

y = (x+2)/(x-3).
Cross-Multiply:

xy - 3y = x + 2

Bring all the terms with x to one side:

xy - x = 2 + 3y

Factor out x:

x(y - 1) = 2 + 3y

x = (2+3y)/(y-1)

and

AR-X, is it a meta or ortho/para director?

one of the question in the ADA sample test said it is para not meta, why?
Hope this helps!
 

dentrilla

10+ Year Member
Aug 15, 2008
169
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Dental Student
beat ya 2 it nze :smuggrin: