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jeffhardy190 · Oct 1, 2009, 12:50 PM

:)Erm Im really tired and Sick right now and I can't firgure out this problem I know its easy I just can't for sum reason help: 2(x+6)=8x I feel retarded because I'm tired and sick D:
thanks people :D :) I need the steps toget the answer so I can see how you did it thanks people that answer this I love you xD

KISS · Oct 1, 2009, 01:26 PM

I do it wierdly:

Count the x's
2 -8 = -6
Count the #'s
12

Ans: 12-6x=0 or 12 = 6x or x = 2

As a check:

2(2+6) = (8)*2); 16=16; so ans is correct

Your probably taught another way which is an exercise in futility. It doesn't help you when the problems get harder.

Perito · Oct 2, 2009, 05:25 AM

2(x+6)=8x

I do it "normally".

Step 1. Use the distributive law on the left side

$2(x+6) = 2x + 12 \, =\, 8x$

Step 2. Subtract 2x from both sides

$2x+12-2x = 8x-2x$

$12 = 6x$

Step 3. Divide both sides by 6

$\frac {12}{6} = 2 \, = \, \frac {6x}{6} = x$

$x = 2$

Yup. Very easy.

KISS · Oct 2, 2009, 01:30 PM

12/6 = 2 = 6x/6 = x

Perito:

You proved my point. The Algebra gets too messy. 2 doesn't = x. You have way too many equal signs.

Unknown008 · Oct 3, 2009, 01:42 AM

Good catch on that one KISS! I didn't notice it! Lol

KISS · Oct 3, 2009, 09:54 AM

I guess in college,I realized that when doing matrix math such as determinants the Algebra gets messy really really fast. I finally also realized that many of my mistakes in anything involving algebra were from two things:

1. Sign changes
2. Using a printed x a y vs a script x and y. The printed x's and y's ended up getting confused

At that level it's important to understand why and it's important to know how to check.

Later you may not be able to learn how to check. I learned recently that the NASA lost a mars lander because someone did some of the calculations in the metric system and other in the English system of measurement. It was in a professional publication.

Then there is the "Does this answer make sense" comes later and "Are the units correct" and tops of significant figures and error bars.

In one area I worked in, 2E16 and 6e16 were effectively the same number.

Zero sometimes is not obtainable in real life.

So, practice your penmanship skills when doing math. A lot of math is memorization. It all started by memorizing that 1+1 = 2.