Thread: Beginning Algebra Final Exam review pt. 2

oK i had this all typed out and my computer died >.<

I have my final exam review here..


Here's the probs:

http://aycu10.webshots.com/image/158...9289183_rs.jpg



Lets start out with 11, 15, 16...



#15.. i did..

x^2-12x=-36

devide by -12..

x^2+x=3

=

2x^2=3

devide by 2

x^2= 3/2

and.. Yeah thats not right. Its supposed to be x=6




Thanks everyone ^^;;


edit: errr.. i guess the attach image thing does work o.0 i never saw it till now..

o.-..

Okay now...

11, 16, 18, 20, 21, 22, and 24 are now (er... for the most part) solved.


This leaves

15,23,25,26 that still arent done.


for 11.. do i gotta factor a x-3 and a x+2 out somehow?????

ok, I have worked out 11 for you (will do the rest later, I'm tried zzzzz)
So anyway....

lets factorise the bottom parts
x^2 - x - 6 = (x + 2) (x - 3)
x^2 - 8x + 15 = (x - 5) (x - 3)

So they cancel the top so we are left with:

1/ (x - 3) + 1/ (x - 5)
get a common denominator
(times (x-3) to the right side, times (x-5) to the left side)
So we get:

(x - 5)/ (x^2 - 8x + 15) + (x - 3)/ (x^2 - 8x + 15)

it becomes:

(2x - 8)/ (x^2 - 8x +15)

and as we know...
(x^2 - 8x +15) = (x - 3) (x - 5)
so answer =
(2x - 8)/ (x - 3) (x - 5)

Happy to help :P I'll be back later, but in the mean-time some other helpful member may have helped you out Goodnight... zzzzzzzzzzz

Ok thanks got that one done.



Just 5 left now..


erm.

ON this page..



...with #16.. would you do... y^3 - y^2 to equal just y??


and on 23... because theres an = sign there and not a plus would you still times the left side by x-3 and the right by x+1??

I tried that and it didnt work for me..

Thanks

so I'll do 16 today :P lol

y^3 - y^2 - 6y = 0

so lets take out the y so we get:

y(y^2 - y - 6) = 0

y^2 - y - 6 FACTORISE to!

(y + 2) (y - 3)

so we now have:

y(y + 2) (y - 3) = 0

this correct? lol




btw on question 11
you can factorise it further to:

2(x -4)/(x - 3) (x - 5)

Ah okay..


I dont need the rest now.. (exam in an hour >.<)

But i suppose you could do them for fun if you'd like! lol!


But thanks for replying on those 2 !!!!!!!!

and..

*sniff* because my exam is today, no more math for me... and more than likely, I wont be back (XD sorry, no offense but i dispise math >.<) so i'd like to give a special thanks to everyone who has dealed with my stupidity over the past ~2 month, and helped me through this, I OWE YOU GUYS!!

But definatelly thanks to Jhevon, helping in the middle of the night, and answering MOST of my questions.. so i could understand it.. you are awesome!

So, I'll be seein ya, math help forum!!

(Ill definately recommend you to anyone i find that needs help )

~Cait