- Thread starter mm_b_sm
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- Apr 12, 2005

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If you are to solve, there are various ways to go about it.

1) Get rid of the fractions (by learning ho wto deal with them, not by being afraid of them).

2) Don't worry about the fractions, since it is quite possible we'll just get them right back.

-7x + 3 = -15/2

Multiply by 2

-14x + 6 = -15

Subtract 6

-14x = -21

Divide by -14

x = -21/(-14) = 21/14 = 3/2

Notice, above, that we ended with fractions despite our efforts.

-7x + 3 = -15/2

Subtract 3

-7x = (-15/2) - 3 = (-15/2) - (6/2) = -21/2

Divide by -7

x = (-21/2)/(-7) = (-21)/[(-7)*2] = 3/2

Same result.

- Joined
- Apr 12, 2005

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- 9,778

That's just not the case all the time. Sometimes it is best.george22 said:The first solution given to you is the best.

Maybe. If that appears to be advantageous.Whenver you are dealing with fractions, multiply the WHOLE equation by the denominator.

Note to Student: Please don't get ONE method stuck in your head - not for ANYTHING. Keep your mind open. Always look around for simpler, more convenient, more useful, or more understandable results. Never, ever think you are clever if you know only one way to proceed.

Go ahead and learn how to work with fractions. You will be better for it.

YUP TK I so agree w/you. Definetly look for the most efficient way based on the information do not use just use one limited way. A good example is system of equations in my experience and this as well.tkhunny said:Note to Student: Please don't get ONE method stuck in your head - not for ANYTHING. Keep your mind open. Always look around for simpler, more convenient, more useful, or more understandable results. Never, ever think you are clever if you know only one way to proceed.

Go ahead and learn how to work with fractions. You will be better for it.

As TK says...."whatever turns you on" :wink:

Start by changing the signs (no need to, really, but useful in some cases):

7x - 3 = 15 over 2

Code:

```
7x - 3 15
-------- = ----
1 2
```

2(7x - 3) = 1(15)

14x - 6 = 15

14x = 21

x = 21/14 = 3/2

...evil even with a single variable to the power 1 :?:tkhunny said:...except "crisscross multiplication" It is evil. :evil:

Ya must be a "reborn mathematician" :wink: