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February 16th, 2016, 04:57 AM   #1
r3v
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8w - 3 = 11

The question is "solve 8w - 3 = 11" help me out please.

and another one is "solve 3(y - 4) = 9"
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February 16th, 2016, 04:59 AM   #2
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8 - w = 11
8 - w - 8 = 11 - 8
-w = 3

If you don't know what to do after this then math is not for you.
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February 16th, 2016, 05:04 AM   #3
r3v
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Quote:
Originally Posted by Monox D. I-Fly View Post
8 - w = 11
8 - w - 8 = 11 - 8
-w = 3

If you don't know what to do after this then math is not for you.
what about another one is "solve 3(y - 4) = 9" friend
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February 16th, 2016, 05:14 AM   #4
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Quote:
Originally Posted by r3v View Post
what about another one is "solve 3(y - 4) = 9" friend
3(y-4) = 9
y-4 = 9/3
y-4 = 3
y = 3+4
y = 7
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February 16th, 2016, 05:22 AM   #5
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Quote:
Originally Posted by r3v View Post
what about another one is "solve 3(y - 4) = 9" friend
Huh? When did you wrote it? I didn't see it.
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February 16th, 2016, 05:56 AM   #6
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Quote:
Originally Posted by Monox D. I-Fly View Post
8 - w = 11
8 - w - 8 = 11 - 8
-w = 3
OP posted this ...

Quote:
8w - 3 = 11
The question is "solve 8w - 3 = 11" help me out please.
Was there an unseen edit?
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February 16th, 2016, 06:52 AM   #7
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Oops, sorry.
8w - 3 = 11
8w - 3 + 3 = 11 + 3
8w = 14
Can you continue?
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February 16th, 2016, 11:57 AM   #8
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8w-3=11
8w=11+3
w=14/8 =1+3/4
3(y-4)=9
y-4=3
y=7

Last edited by manus; February 16th, 2016 at 12:12 PM. Reason: forgot something
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February 16th, 2016, 12:12 PM   #9
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You can, of course, reduce the fraction 14/8 to 7/4 and, if you wish, reduce that to the "mixed fraction" 1 and 3/4.

r3v, all of these problems can be solved by "undoing" what has been done to the unknown value.

In the first, 8- w= 11, we can think "on the right side, 8 has been added to -w. I can undo that by subtracting 8". And, of course, whatever we do to one side, we must do to the other. Doing that, we have -w= 11- 8= 3. Now, the only problem is that we have "-w" when we want "w". Thinking of that as "-1 times w", we undo it by dividing both sides by -1: -w/-1= 3/-1 so w= -3.

In the second, 3(y- 4)= 9, we immediately see that the parentheses on the left side are multiplied by 3. We undo that by dividing both sides by 3: y- 4= 9/3= 3. Now, the only reason we do not have y by itself is that 4 is subtracted from it. We can undo that by adding 4 to both sides: y= 3+ 4= 7.
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February 16th, 2016, 04:31 PM   #10
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Quote:
Originally Posted by skeeter View Post
Was there an unseen edit?
An edit is unseen if it's done very soon after the original post.
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