Addition: 3/5x-20 + 4/5 = 3/5x-20

B

BB

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This is what i have but does not look correct can you help Thxs

3/5x-20 + 4/5 = 3/5x-20

-3/5x-20 + 4/5 = -3/5x-20

4/5=x/5

5x/5=20/5

x=4
 
Do you mean:

....1).. \(\displaystyle \L \;\frac{3}{5}x\,-\,20\,+\,\frac{4}{5}\,=\,\frac{3}{5}x\,-\,20\)

....2)..\(\displaystyle \L \;\frac{3}{5x\,-\,20}\,+\,\frac{4}{5}\,=\,\frac{3}{5x\,-\,20}\) ?

Or maybe something else?
 
addition

jonboy
#2 is what i am working on.
Thxs
 
Multiply everything by 5 and rethink it.

Use more parentheses to calrify meaning.

Show your work. What are your thoughts on this solution?
 
addition

should problem read this way

3/5x-20 + 4/5 = 3/5x-20

3 + 4(x-4) = 3(x-4)

3+4x = 16 = 3x - 12

4x = 19 = 3x - 12

x^2 + -4 - 3 = -3 + x^2 -4x

x^2 - 16 = 0

(x+4) (x-4) = 0
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Re: addition

BB said:
3/5x-20 + 4/5 = 3/5x-20

3 + 4(x-4) = 3(x-4)
Click to expand...
Close. There should be no (x-4) on the RHS.

Not close: 3/5x-20 Notation is still bad. Write 3/(5x-20) to write what you mean.

Not Close: If the problem statement were as shown below, could you solve it?

Fred + (4/5) = Fred
 
addition

Sorry tkhunny i will try better all new to me.

3/(5x-20) + 4/5 = 3/(5x-20)

3 + 4(x-4) = 3

3 + 4x = 16 = 3

x^2 + -4 - 3

x^2 -16 = 0

(x+4) (x-4) = 0
 
Re: addition

BB said:
Sorry tkhunny i will try better all new to me.
Click to expand...
No worries, as long as you can take correction. :D

3/(5x-20) + 4/5 = 3/(5x-20)

3 + 4(x-4) = 3
Click to expand...
Good.
3 + 4(x-4) = 3

3 + 4x = 16 = 3
Click to expand...
No good. Two equal signs?
3 + 4x = 16 = 3

x^2 + -4 - 3
Click to expand...
Super no good. I cannot tell what went on, here. Whither went the equal sign? From whence came the "^2"? x never just magically turns into x^2. If that ever happens again, set up some alarms so you won't think it's okay.

Slowly, carefully...

3 + 4x - 16 = 3

Subtract 3 from each side

4x - 16 = 0

Add 16 to each side.

4x = 16

Divide each side by 4

x = 4

Now, one might THINK one is done. One is NOT done. You tell me why. Soroban gave you a hint on another thread. I gave you "Fred", my version of a nice hint, above.
 
addition

tkhunny
I don't want to say i'm not getting this but i'm not my guess would be that this is a extrenuous problem an i correct or way off.
 
Well, no one can help you if no one can figure out where you are. I'm not real sure how to proceed, except to encourage you to seek local professional assistance from some academic counselor. You obviously have some important holes in your education. Maybe we can help, but I'm not sure. There has been more than enough discussion on this problem, I think. Where does that leave us?
 
BB said:
This is what i have but does not look correct can you help Thxs

3/5x-20 + 4/5 = 3/5x-20

-3/5x-20 + 4/5 = -3/5x-20

4/5=x/5

5x/5=20/5

x=4
Click to expand...


Can we try a bit of common sense here??

you've got this:

3/(5x - 20) + (4/5) = 3/(5x - 20)


LOOK at this carefully!!! Do you see that it says

"something" + (4/5) = "that same something"

Now.....

Use your mathematical knowledge. Is it possible for some number, plus (4/5), to equal the number you started with??

Of course it isn't possible!!! So, there is no value for x which will make the original equation true.

You've been shown some algebraic methods to arrive at the same result....there is no value of x which makes the original equation true. But, I think having some "number sense" is just as good a tool as algebraic skills.
 
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