Question

Simplify the rational expression
3r^2-9r
---------
r-3
Identify any excluded values.

Answer 1

\[\LARGE {3r^2-9r\over r-3}={3r^2-3^2r\over r-3}={3r(r- 3)\over r-3}=3r\]

Answer 2

Can you show how you got those numbers? I'm pretty lost.

Answer 3

you just put those numbers in

Answer 4

Which number's where I don't understand what your telling me :o

Answer 5

ok here's what I've done:
\[\LARGE 9=3^2\] right?
and from
\[\LARGE (3r^2-9r)=(3r^2-3^2r)\]
are we clear till here? :)

Answer 6

Yes! Thank you so much :D

Answer 7

ok hold on... now we have: from:
\[\LARGE (3r^2-3^2r)=3r(r-3)\]
because they are equal, if we multiply them out, it becomes as it was in the beginning...
\[\LARGE 3r(r-3)=3r\cdot r-3r\cdot 3=3r^2-3^2r \]
so once we have:
\[\LARGE {3r(r-3)\over r-3}=3r\cdot {r-3 \over r-3}=3r\cdot 1=3r\]
do you get it ? :)

Answer 8

Yes. I get it, thank you for explaining this to me.

Answer 9

You're welcome :)