Question

i need help with the following attachment ....

Answer 1

What do you need help with specifically. Long problem, has a lot of work on it already?

Answer 2

to check #6 if i did it correctlty?

Answer 3

Good work, unfortunately some algebra mistakes. When working on an equation, If you do something to one side, you have to do to the other side (all terms). Likewise when you do something to a radical expression p/q; you must do top and bottom.

Answer 4

ahh i see so then that would make it x = 400*666.7?

Answer 5

On your first step you square, square root (400 + x^2) and 1000 but you didn't square 1500. In any event, it is not recommended to go this route. When you want to square to remove radical, you should first isolate the radical to one side and all other terms to the other side. So your first step, it is recommended to multiply through by sq rt (400+x^2) not to remove radical but to cancel it from the denominator.

Answer 6

okay give me a sec and ill do it

Answer 7

so x=(2/3)?

Answer 8

That was a big jump from one step to the next, may be it's right but the next step is \[-1000(\sqrt{400+x ^{2}}) +1500x=0\]

Answer 9

aww no im not right i did something else..okay let me see if i can get it

Answer 10

is the next step moving the "1000" over the "=" sign making it a positive?

Answer 11

You can, but it is just as easy to divide by -1000.

Answer 12

so it just basically cancels out?

Answer 13

\[\sqrt{400+x ^{2}}=(-1500x)/(-1000)\]

Answer 14

wouldnt it be positive 1000?

Answer 15

oh wait nevermind...

Answer 16

would it be -1500x=\[\sqrt{400+x ^{2}}\](-1000)
?

Answer 17

The purpose of doing this is to isolate the radical, then square it and get rid of it\[400+x ^{2}=(9x ^{2})/4\]

Answer 18

how did you get \[(9x ^{2})/4??\]

Answer 19

\[[(-1500x)/(-1000)]^{2}=(15x/10)^{2}=(3x/2)^{2}\]

Answer 20

does x= -31???

Answer 21

I am not confident in your work, you jump too many steps; it's not the way you do mathematics. Work it from there. I'll check it later. It is definitely not -31

Answer 22

okay i went from your step to \[x^{2}=(9^{x ^{2}}-400]??

Answer 23

\[x ^{2}=(9x ^{2}-400)\]

Answer 24

9xsquared /4 that is sorry

Answer 25

i got \[100\sqrt{2}\]

Answer 26

\[x ^{2}-(9x ^{2})/4=-400\]

Answer 27

\[x ^{2}(1-[9/4]=-400\]

Answer 28

\[x ^{2}(-5/4)=-400\]

Answer 29

isee how your getting this:D

Answer 30

\[x ^{2}=400(4/5)\]

Answer 31

now we divide -400 and (-5/4)?

Answer 32

Yes\[x =\sqrt{320}\]\[x =6\sqrt{5}\]

Answer 33

ahhh i had \[\sqrt{200}\] .... boy was i off ... well thank you so much for helping me i have a better understanding for calculus im in 10th grade so im new to this ... you were tons of help ..bye bye?!

Answer 34

Good work, you are doing good. It took years of working with a tutor for me to feel this comfortable.