9x^2 + 25y^2 = 225

The foci are:

(-4, 0) and (4, 0)
(0, -4) and (0, 4)
(-5, 0) and (5, 0)

Question

9x^2 + 25y^2 = 225

The foci are:

(-4, 0) and (4, 0)
(0, -4) and (0, 4)
(-5, 0) and (5, 0)

anonymous · Answer

Im preatty sure its c but how do i figure it out

anonymous · Answer

@Directrix @inkyvoyd @mathmale

anonymous · Answer

@pink33

anonymous · Answer

Okay so have you tried to firgure this out?

anonymous · Answer

i have a calculator online that just does it for me but id like to know how to do it

anonymous · Answer

Oh,okay somethimes those calculator are wrong so I explain how to do it

anonymous · Answer

ok please and thankyou

directrix · Answer

>Im preatty sure its c  

I think that "c" is not correct. We will see after @pink33 does the explanation.

anonymous · Answer

Okay I don't think c is correct

anonymous · Answer

How did you get c?

anonymous · Answer

just finding the x and y interepts

anonymous · Answer

nvm i guess found the awnser myself

directrix · Answer

This is not an explanation but may help.  @dirtydan667

anonymous · Answer

ahhh yes wolfram alpha

directrix · Answer

Explanation courtesy of Phone-A-Friend @Mackenzie2013

directrix · Answer

@dirtydan667   ^^^^^

anonymous · Answer

thanks for finding that

directrix · Answer

You are welcome.