Question

Simplify completely quantity 12 x plus 36 over quantity x squared minus 4 x minus 21 and find the restrictions on the variable. !!!!!!!!!!!!!!!!!!!!

Answer 1

I'm not very good at these myself, but as I see that no one else has come to help...

so you have been given
12x + 36
------------
x² - 4x - 21

then you can factor out a 12 from the numerator -> 12(x+3)
and factor the denominator -> (x+3)(x-7)

follow so far? :)

Answer 2

Yes, thanks, and then the x+3 cancels out, I think, no?

Answer 3

correct :)
and know that by canceling them out
you will have a domain restriction of x ≠ -3

Answer 4

oh cool, yea, I think I understand the main part of this. I'm confused with those restrictions:(

Answer 5

you know how you can't divide something by 0 ?
well, then, that's a domain restriction
so when you get 12 over (x-7)
x-7≠0

Answer 6

yes, but does the 12 have anything to do with that?

Answer 7

not really, no :P

Answer 8

maybe the range restrictions?
but I'll have to look that up ;)

Answer 9

Maybe, i didn't learn anything about that, but thanks so much for explaining:)

Answer 10

you're welcome :) glad I could help