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Stupid Algerbra

by Jinglander » Tue Aug 10, 2010 11:40 am
I have to solve this for Y. Here are the steps that I took where did I go wrong.

100-y=100,000/(100+x)
Subtract 100 from both sides

-y=100,000/(100+x)-100

multiply both sides by -1
y=-100,000/(100+x)+100

The anser given is
y=100-[100,000/(100+x)]

Are these the same things if this were so then

7-6
would eauly
-7+6 which it does not

Where am I going wrong
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by kvcpk » Tue Aug 10, 2010 11:45 am
Jinglander wrote:I have to solve this for Y. Here are the steps that I took where did I go wrong.

100-y=100,000/(100+x)
Subtract 100 from both sides

-y=100,000/(100+x)-100

multiply both sides by -1
y=-100,000/(100+x)+100

The anser given is
y=100-[100,000/(100+x)]

Are these the same things if this were so then

7-6
would eauly
-7+6 which it does not

Where am I going wrong
The part in Bold is your mistake.
a-b When multiplied by -1 becomes b-a
Hence,
-100,000/(100+x)-100 when multiplied by -1 becomes
100-100,000/(100+x)


Hope this helps!!
"Once you start working on something,
don't be afraid of failure and don't abandon it.
People who work sincerely are the happiest."
Chanakya quotes (Indian politician, strategist and writer, 350 BC-275BC)
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by Jinglander » Tue Aug 10, 2010 11:52 am
b-a
is the same as -b+a still dont see the error
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by kvcpk » Tue Aug 10, 2010 11:56 am
Jinglander wrote:b-a
is the same as -b+a still dont see the error
-b+a is equal to a-b
It is different from b-a

A = B-C
When you multiply both sides by -1,
-1 * A = (-1)*B - (-1)*C
-A = -B-(-C)
-A = -B+C
-A = C-B

Hope this helps!!
"Once you start working on something,
don't be afraid of failure and don't abandon it.
People who work sincerely are the happiest."
Chanakya quotes (Indian politician, strategist and writer, 350 BC-275BC)
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