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kaybug
11-03-2008, 12:44 PM
Gotta find x, basically.

7/8x - 1/4 + 1/2x = 3/4 + x
My attempts:
1) 7/8x - 1/4 + 1/2x = 3/4 + x
8(7/8x - 1/4 + 1/2) = 8 (3/4 + x)
7x + 2 + 4x = 6 + 8x
11x + 2 = 6 + 8x
11x + 2 - 2 = 6 - 2 + 8x
11x = 4 + 8x
11x = 4/11 + 8/11x
Ack! Stuck!

2) 7/8x - 1/4 + 1/2x = 3/4 + x
7/8x + 1/2x - 1/4 = 3/4 + x
11/8x - 1/4 + 1/4 = 3/4 + 1/4 + x
11/8x = 4 + x
hmm.. tried continueing but no answer apeared.

The answer is: x = 8/3
Yeeahh, I'm pretty lost.

41.68 = 4.7 - 8.6y
My attempt:
41.68 = 4.7 - 8.6y
100(41.68) = 100(4.7 - 8.6y)
4168 = 470 - 860y
4168 + 470 = 470 + 470 - 860y
4638 = 860y
4638/860 = 860/860
???? = y
@_@ I'm pretty lost on what to do with that one because by hand I get something along the lines of y = 5.740 etc, and by calculator I get something along the lines of y = 5.393 etc.

I'm not really sure what I'm doing wrong.. can you see my mistake, or do you do the steps differently than what I did?
As well, anyone know what topic of algebra this is? XD I've been trying to find help for this problem for a couple of days, but I can't figure out what kind of algebra it is, so my searching has been pretty fruitless.

Subhotosh Khan
11-03-2008, 01:08 PM
Gotta find x, basically.

7/8x - 1/4 + 1/2x = 3/4 + x
My attempts:
1) 7/8x - 1/4 + 1/2x = 3/4 + x
8(7/8x - 1/4 + 1/2) = 8 (3/4 + x)
7x + 2 + 4x = 6 + 8x <<< That should be "-2 + 4x =..."
11x - 2 = 6 + 8x
11x + 2 - 2 = 6 + 2 + 8x
11x = 8 + 8x <<< Isolate 'x'

11x - 8x = 8

3x = 8

x = 8/3
Check

7/8x - 1/4 + 1/2x = 3/4 + x

7/8 * (8/3) - 1/4 + 1/2* (8/3) = 3/4 + 8/3

7/3 - 1/4 + 4/3 = (9+32)/12

(7*4 - 3 + 4*4)/12 = 41/12

41/12 = 41/12 .............checks

11x = 4/11 + 8/11x
Ack! Stuck!

2) 7/8x - 1/4 + 1/2x = 3/4 + x
7/8x + 1/2x - 1/4 = 3/4 + x
11/8x - 1/4 + 1/4 = 3/4 + 1/4 + x
11/8x = 4 + x
hmm.. tried continueing but no answer apeared.

The answer is: x = 8/3
Yeeahh, I'm pretty lost.

41.68 = 4.7 - 8.6y
My attempt:
41.68 = 4.7 - 8.6y

Isolate y

41.68 - 4.7 = - 8.6 y

36.98 = -8.6 y

y = - 36.98/8.6

100(41.68) = 100(4.7 - 8.6y)
4168 = 470 - 860y
4168 + 470 = 470 + 470 - 860y
4638 = 860y
4638/860 = 860/860
???? = y
@_@ I'm pretty lost on what to do with that one because by hand I get something along the lines of y = 5.740 etc, and by calculator I get something along the lines of y = 5.393 etc.

I'm not really sure what I'm doing wrong.. can you see my mistake, or do you do the steps differently than what I did?
As well, anyone know what topic of algebra this is? XD I've been trying to find help for this problem for a couple of days, but I can't figure out what kind of algebra it is, so my searching has been pretty fruitless.

Denis
11-03-2008, 04:53 PM
Gotta find x, basically.
7/8x - 1/4 + 1/2x = 3/4 + x

Keep it as simple as possible:
Start by getting terms with x together:
7x/8 + x/2 - x = 3/4 + 1/4
7x/8 + x/2 - x = 1
Multiply each term by LCD 8:
7x + 4x - 8x = 8

OK??

kaybug
11-03-2008, 04:54 PM
Thank you both SO much! <3 I *finally* understand what I was doing wrong. :D