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Homework Statement
Homework Equations
none
The Attempt at a Solution
Is this correct?
Thanks.
The answer is correct.Homework Statement
[ ATTACH=full]101053[/ATTACH]
Homework Equations
none
The Attempt at a Solution
[ ATTACH=full]101054[/ATTACH]
Is this correct?
Thanks.
Plug it in and see if it works.Homework Statement
View attachment 101053
Homework Equations
none
The Attempt at a Solution
View attachment 101054
Is this correct?
Thanks.
I understand where I made the error, the return trip speed decreased by 200 km/h, so it should have been (x-200) not (x+200), so I have corrected my answer:The answer is correct.
There are errors in your work starting with the table.
If x is the speed from Tokyo to Bangkok then reducing that by 200 gives a speed of x - 200 from Bangkok to Tokyo. Etc.
There's still a problem, x is the Tokyo to Bangkok speed. That can't be 600mph. 600 - 200 is 400, and that doesn't work out.I understand where I made the error, the return trip speed decreased by 200 km/h, so it should have been (x-200) not (x+200), so I have corrected my answer:
[ ATTACH=full]101104[/ATTACH]
Thanks for the help! :)
There's still a problem, x is the Tokyo to Bangkok speed. That can't be 600mph. 600 - 200 is 400, and that doesn't work out.
So, where is the problem?
You made a couple of errors.
Sign errors in going from
−960000=2x2−400x−960000=2x2−400x-960000=2x^2-400x to
2x2+400x−960000=02x2+400x−960000=02x^2+400x-960000= 0 It should be
2x2−400x+960000=02x2−400x+960000=02x^2-400x+960000= 0 But there is no real solution to that.
I don't understand what you mean, can you please explain?The problem is that it's the Tokyo to Bangkok time that's smaller, because the speed is greater. When you subtract to get 2 hours, you need to subtract in the opposite order.
If x > 200, thenI tried doing it this way, but as you said there is no real solution.
I don't understand what you mean, can you please explain?
So even if I switch these two, can I not get the same answer I had originally? How does switching the two help with the answer to the problem? or is it just the proper way to write it?If x > 200, then
4800x−200>4800x4800x−200>4800x\displaystyle \frac{4800}{x-200}>\frac{4800}{x}.
So you had these reversed.
It's what is needed of you want to make everything consistent.So even if I switch these two, can I not get the same answer I had originally? How does switching the two help with the answer to the problem? or is it just the proper way to write it?
So like this:It's what is needed of you want to make everything consistent.
As I stated in my first reply, the answer you gave for the time from Bangkok to Tokyo was correct. (600 km/hr)
But you had a number of inconsistencies.
Added in Edit:
You should get x = 800. Then x- 200 = 600, the answer.
No.Not like that.
You should get x = 800. Then x- 200 = 600, the answer.
Right. And they did not make algebra mistakes. You did.This is an example from my lesson that I have been using as a reference to solve my problem:
View attachment 101173
View attachment 101174
No.Not like that.
The first three lines are correct.
After that, there are at least two Algebra mistakes.
Yes. That looks to be correct.View attachment 101177
4800x - 4800x + 960 000 = 2x^{2} - 400x (960 000 is positive because I multiplied -4800 and -200)
960 000 = 2x^{2} - 400x (Now I move 960 000 to the right side and it becomes -960 000)
2x^{2} - 400x - 960 000 = 0
x^{2} - 200x - 480 000 = 0
(x+600) (x-800) = 0
x= -600 or x = 800
Does this make more sense? did I fix the algebra errors? if not please show me where I made errors.
So since x = 800, we need to solve for the jets's speed from Bangkok to Tokyo, so (like you said) sub x = 800 into x- 200, which gives:You should get x = 800. Then x- 200 = 600, the answer.