Question

[y^2-2y/y^2+7y-18] X [y^2-81/y^2-11y+18]
Simplify the rational expression.

Answer 1

\[\frac{ y^2-2y }{ y^2+7y-18 } * \frac{ y^2-8 }{ y^2-11y+18 }\]

Answer 2

is that correct?

Answer 3

y^2-81. :P

Now y2-2y = y(y-2), y2-81 = (y+9)(y-9), ok?

Answer 4

you have to factor, multiply, and cancel out terms. I can't figure out how to factor and multiply

Answer 5

I can help but is my equation correct?

Answer 6

yeah except on the top part of the second one it's an 81 not an 8

Answer 7

okay

Answer 8

okay
\[\frac{ y(y-2) }{ (y-2)(y+9) } * \frac{ (y-9)^2 }{ (y-9)(y-2) }\]

Answer 9

do you understand how I got that?

Answer 10

yes. thanks! so now do I just cancel?

Answer 11

yes

Answer 12

you should get
\[\frac{ y }{ y+9 } * \frac{ y-9 }{ y-2 }\]

Answer 13

okay, thanks. are there more steps?

Answer 14

if you multiply

Answer 15

(y^2-9y)/(y^2+7y-18)

Answer 16

\(y^2 - 81 \neq (y - 9)^2\)
\(y^2 - 81 = (y - 9)(y + 9)\)

Answer 17

Hey there! I see that you are new to OpenStudy.
This is a great website on getting help with questions
of any subject. It is a fun way of learning!
If you have any additional questions involving the website
feel free to ask the people with the purples A's next to
their name. They are the ambassadors and will answer all
your questions regarding the site. And also read the
http://openstudy.com/code-of-conduct so you know the
rules and regulations :)
Have a great day and I hope you have fun!

Answer 18

\[\frac{ y^2-2y }{ y^2+7y-18 } * \frac{ y^2-81}{ y^2-11y+18 }\]
\[\frac{ y(y - 2) }{ (y + 9)(y-2) } * \frac{ (y + 9)(y - 9)}{(y - 9)(y - 2)}\]
\[\frac{y}{y + 9} * \frac{y + 9}{y - 2} = \frac{y}{y-2}\]

Answer 19

I think you are supposed to divide out common factors to cancel. like y-2 and y-2

Answer 20

\[\frac{ y(y - 2) }{ (y + 9)(y-2) } * \frac{ (y + 9)(y - 9)}{(y - 9)(y - 2)}=\]
\[\frac{ y(y - 2)(y + 9)(y - 9) }{ (y + 9)(y-2)(y - 9)(y - 2) }\]
Canceling stuff
\[\frac{ y\cancel{(y - 2)}\cancel{(y + 9)}\cancel{(y - 9)}}{ \cancel{(y + 9)}\cancel{(y-2)}\cancel{(y - 9)}(y - 2) }=\frac{y}{y - 2}\]