[SPLIT] solving 3x - 2x + 5 = 5

[redranger7018]

Hello everyone, I got another problem here. I basically understand this example that I have in the book, but this other practice problem isn't the same as the example and I'm not sure if I doing it right, ok here is the example:

Example_#07 Solve for x:
5x + 2 - 4x = 7 - 9
(5x - 4x = 1x)
(7 - 9 = 2)
(-2 - 2 = -4)
Answer: (1x = -4, or x = 4)

When I try this out on a practice problem it works out real good, like this:
-8x + 4 + 9x = -1 + 7
(-8x - 9x -1x)
(-1 + 7 = 6)
(6 - 4 = 2)
Answer: (-1x = 2, or x = 2)

Ok here is the problem that I'm having with this practice problem:
3x - 2x + 5 = 5
(3x - 2x + 5 = 6x)
(6 - 5 = 1)
(6x = 1, or x = 6)

The book doesn't show how to do this one, am, I getting it right or not?

 

[jonboy]

Ok here is the problem that I'm having with this practice problem.
3x - 2x + 5 = 5
(3x - 2x + 5 = 6x)
(6 - 5 = 1)
(6x = 1, or x = 6)

The book doesn't show how to do this one, am, I getting it right or not?

No. You can check and see by plugging your variable back in your equation.

I am not even to work that out you can tell that does not work: \(\displaystyle \L \;3(6)\,-\,2(6)\,+\,5\,=\,5\)

Here is what I would do: \(\displaystyle \L \;3x\,-\,2x\,+\,5\,=\,5\)

Combine like terms on the left side of the equation: \(\displaystyle \L \;x\,+\,5\,=\,5\)

Subtraction Property ( - 5) : \(\displaystyle \L \;x=0\)

Check: \(\displaystyle \L \;3(0)\,-\,2(0)\,+\,5\,=\,5\,\to\,0\,+\,5\,=\,5\,\to\,5=5\)

That is all there is to it.

 

[stapel]

1) If 1x = -4, then x = -4, not +4.

2) If -1x = 2, then x = -2, not +2.

3) If 6x = 1, then x = 1/6, not 6.

Eliz.

 

[Denis]

5x + 2 - 4x = 7 - 9
(5x - 4x = 1x)
(7 - 9 = -2)
(-2 - 2 = -4)
Answer: (1x = -4, or x = 4)

Red, you've got to stop doing those that way, else you'll never get anywhere!

You've got:
5x + 2 - 4x = 7 - 9
Subtract 2 from each side to have the x's together:
5x - 4x = 7 - 9 - 2
Now simplify:
x = -4
That's it!

There's NO NEED to write down stuff like (7 - 9 = -2); that's done IN YOUR HEAD; capish?

Above is my opinion...

 

[redranger7018]

Hi everyone, I’d like to thank all those that have responded to my post. You all have made learning algebra a little easier, especially since I’m dyslexic with numbers. I don’t see them reversed, but I do get them in the wrong order with out even knowing I have done so. It’s hard to keep thing straight in my head. One of the things that help’s a lot is to color code my work in ms-word because, I don’t confuse colors. I do realize that there is a shorthand technique used in algebra, but since I’m just getting started I have to do it the long way, after 43 years of doing thing's one way it’s hard to just do things in a new and different way other then the old basic mathematic way of doing things. I tried to work out this problem again and I think I see what my mistake was.

3x - 2x + 5 = 5
(3x – 2x = 1x)
(5 + -5 = 0)
Answer: (1x = 0, or x = 0)

Again thanks for your help.

 

[jonboy]

Original: 3x - 2x + 5 = 5 ......Work: (3x – 2x = 1x)

Maybe I just do not understand your method but how are you getting another x?


Ok well you got a correct anwer......

 

[redranger7018]

After I posted the first problem I went to a web site called http://www.algebrahelp.com where they have an online algebra calculator. this is what it shot back.

Simplifying
3x + -2x + 5 = 5

Reorder the terms:
5 + 3x + -2x = 5

Combine like terms: 3x + -2x = 1x
5 + 1x = 5

Add '-5' to each side of the equation.
5 + -5 + 1x = 5 + -5

Combine like terms: 5 + -5 = 0
0 + 1x = 5 + -5
1x = 5 + -5

Combine like terms: 5 + -5 = 0
1x = 0

Solving
1x = 0

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Divide each side by '1'.
x = 0

Simplifying
x = 0

 

[stapel]

Ah. With the line-by-line worded explanations, it makes much more sense. Thank you.

Eliz.