Challenge Decimal Problem

[peggyskold]

Can someone tell me the correct way to solve this? Here is what I have done--is this correct?

x/2+-8=4x-6
Since x/2 =1/2x
1/2x+-8=4x-6
0.5x+-8=4x-6
0.5x+-8=4x-6
-0.5x -0.5x
3.5x-6+6=-8+6
3.5x=-2
/3.5 /3.5
x=~-0.57

 

[Deleted member 4993]

Can someone tell me the correct way to solve this? Here is what I have done--is this correct?

x/2+-8=4x-6
Since x/2 =1/2x
1/2x+-8=4x-6
0.5x+-8=4x-6
0.5x+-8=4x-6
-0.5x -0.5x
3.5x-6+6=-8+6
3.5x=-2
/3.5 /3.5
x=~-0.57

Looks good to me...

 

[peggyskold]

one more decimal challenge

I just wasn't sure about this one because I ended up with one of those repeating can anyone help me with this? Thank you so much!

4x-8=x/3+20

 

[wjm11]

Hello, Peggyskold,

Good job on the first problem. But you don't really need anyone else to tell you if you've arrived at the correct answer. There is a very simple method to check yourself. Just take your answer and plug it into the original problem and see if it works.

And just because you got a repeating decimal on the second problem doesn't necessarily mean your answer is wrong.

4x-8=x/3+20

Multiply both sides by 3: 12x - 24 = x + 60

Subtract x from both sides: 11x - 24 = 60

Add 24 to both sides: 11x = 84

Divide both sides by 11: x = 84/11 = 7.636 (approx.)

To check, plug (84/11) in for x in the original problem:

4(84/11) - 8 = (84/11)/3 + 20

22.545 = 22.545

Make sense?

This is a great habit to get into to check all your work (especially on tests!).

 

[rexmorgan]

Can someone tell me the correct way to solve this? Here is what I have done--is this correct?

x/2+-8=4x-6
Since x/2 =1/2x
1/2x+-8=4x-6
0.5x+-8=4x-6
0.5x+-8=4x-6
-0.5x -0.5x
3.5x-6+6=-8+6
3.5x=-2
/3.5 /3.5
x=~-0.57

I would be careful where you do your subtraction of 0.5x from both sides. You seem to do two steps here together. While not necessarily wrong when you are having problems or think you are you should be very careful not to lump steps together. Often times mistakes that people make lie in those types of things. However you do absolutely have the correct answer.