Question

Please help have to spend the rest of my weekend catching up...
student solved 6x+4=2(x−8) in four steps as shown:


Step 1: 6x+4=2x−8
Step 2: 4x+4=−8
Step 3: 4x=−12
Step 4: x=−3

Which statement is an accurate interpretation of the students work?
Question 1 options:

The correct solution is x=−3


The student made an error in Step 1.


The student made an error in Step 3.

Answer 1

@roadjester

Answer 2

What do you think @narissa ?

Answer 3

No. Look carefully if the student correctly used the distributive property.

Answer 4

oh B

Answer 5

Can you tell me how you got that answer?

Answer 6

i guessed... im kinda slow in math

Answer 7

sorry my computer froze

Answer 8

Look at this website and compare it to the steps you are given.
http://www.coolmath.com/prealgebra/06-properties/05-properties-distributive-01

Answer 9

he didnt multiply the numbers correctly

Answer 10

I agree with @a1234
The distributive law was incorrectly applied.

Answer 11

so b is the correct answer..?

Answer 12

Yes, b is the correct answer.

Answer 13

Add 8 on both sides,so that the equation will be 6x+12 = 2x. Then divide both sides by 2 so that the equation will be 3x+6 = x. Divide x on both sides so that you get 3+6 = x. S0 x = 9. That or do distributive property on the right side so that this is how the equation looks like: 6x+4 = 2x-16. Then add 16 on both sides, now you have 6x+4+16 = 2x. Rewrite the equation as 6x+20 = 2x.Then divide both sides by 2 so that you get: 3x+10 = x divide by x on both sides so that its 3+10 = x. So x = 13, so depending on how you do the problem the x could equal either 9 or 13.

Answer 14

@StudiousHojea I see you want to help, but dividing both sides by x does not work (and it's not relevant to the problem).

Answer 15

How does it not work and how is it not relevant? I am not annoyed or anything, just curious.

Answer 16

Because you are trying to find what the variable is. If you divide out the variable, you're not really getting any results.

When you solve an equation you try to separate the variable from the constants.
So...
6x + 4 = 2x - 16
4x = -20
x = -5

Answer 17

Actually, if you divide out the variable in 6x + 4 = 2x - 16, it does work, but it has to be done correctly.

That would be 6 + 4x = 2 - 16x
4 = -20x
x = -5
So my response above was partly incorrect

Answer 18

Oh! Now get it. So after writing 6x+4 = 2x-16, you have to subtract 4 from both sides so that you get 6x = 2x-20. Then you subtract 2x from both sides so its 4x = -20 and that is how you get x = -5?

Answer 19

Correct!

Answer 20

Wow! Thank you! I think I understand math better a little.

Answer 21

You're welcome. And good questions!

Answer 22

Thanks! Have a nice day! Well, I think we are going to talk again sometime today, but for now, have a good day!

Answer 23

What grade are you in? I am in 10th