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tombfan91
06-11-06, 03:08
-6x+3(4x - 1) =9

does anybody know how to solve this?

PARANOIA
06-11-06, 03:09
Multiply the set of (4x - 1) by 3. Result:

-6x + 12x - 3 = 9

Combine like terms. Subtract 6x from 12x. Add three to both sides to even terms. Result:

6x = 12

Divide both sides by six. Result:

x = 2

Then check, substitute 2 for x.

-12 + 3(8 - 1) = 9
-12 + 21 = 9
9 = 9

Solution set: {2}

tombfan91
06-11-06, 03:19
i lost you when you said combin like terms could you explain that part again?

PARANOIA
06-11-06, 03:28
The combination of like terms is basically the adding, subtracting, etc. of variables as though they were actual numbers.

So:

With 4x + 3x, to combine like terms, you would add 4 and 3, therefore making 7x.

With 8x - 3x, combine like terms. Result: 5x

With 4x * 4x, combine like terms: Result: 16x

Etc, etc, etc.

-

So, to extend Step 2, after you've combined the "X"'s, you should be left with this:

6x - 3 = 9

To solve for x, you want to separate x into one side. So, you would add 3 to both sides.

6x - 3 + 3 = 9 + 3
6x = 12

From there, you should be able to solve the rest of the equation by dividing both sides by six, therefore figuring out the value of x.

tombfan91
06-11-06, 03:35
oooo ok i get but i though since thier are 2 x and theirs an addition sign you would do it liek this
6+2x or something liek that.

tombfan91
06-11-06, 03:44
i'm really sorry to bother you again, but could you elp me one more time? if you have time? 1/8x - 5 = 3 " solv e the equation to different ways : A multiply and subract B. subtract and multiply. explain which methos you prefer and why

PARANOIA
06-11-06, 03:52
To multiply and subtract, before you do anything, multiply both sides by 8 to simplify x. You should end up with this:

x - 40 = 24

Then you can add 40 to both sides, and receive:

x = 64

To subtract and multiply, add 5 to both sides first, giving y:

1/8x = 8

Then you can multiply both sides by 8, and receive the same result:

x = 64

-

Logically, they present you the same answer. However, the method you prefer is really your choice. Personally, I would go with "subtract and multiply" because it's easier to multiply one term than it is to multiply two. However, it's all your preference on which seems faster.

just croft
06-11-06, 08:40
I just finnished that subject on math class, its wiked!