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# Is this correct (maths) watch

1. Can i re-write n! as n(n-1)(n-2)! ?
2. No just try out a value for n.
Such as n=4
4!=24
4(3)(2)!=24! Therefore they aren’t the same
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3. (Original post by Howie_2114)
No just try out a value for n.
Such as n=4
4!=24
4(3)(2)!=24! Therefore they aren’t the same
I mean the factorial is on the last one
so it's 4x3x2!
factorial applies to the last number
4. Yeah, provided n is greater than or equal to two
5. Is it yes or no xD. oNE SAYS yes one says no. Can someone please confirm the answer?
6. (Original post by mariejuana)
Is it yes or no xD. oNE SAYS yes one says no. Can someone please confirm the answer?
Yes.

n! = n(n-1)! = n(n-1)(n-2)! = n(n-1)(n-2)(n-3)! ... and so on
7. (Original post by Howie_2114)
No just try out a value for n.
Such as n=4
4!=24
4(3)(2)!=24! Therefore they aren’t the same
4(3)(2)! is not the same as (4*3*2)!

4(3)(2)! = 4*3*(2!) = 4*3*2 = 24
8. (Original post by Maivnek)
Yes.

n! = n(n-1)! = n(n-1)(n-2)! = n(n-1)(n-2)(n-3)! ... and so on
ok
SO i have
n(n-1)(n-2)!/ 2(n-2)!
Would it be correct to simplify it like so
n(n-1)!/2!
and could this be further simplified ?
9. (Original post by mariejuana)
ok
SO i have
n(n-1)(n-2)!/ 2(n-2)!
Would it be correct to simplify it like so
n(n-1)!/2!
and could this be further simplified ?
The exclamation marks cancel too.
You're doing factorial of n-2 divided by factorial of n-2 so you should cancel out all of those extra terms.
10. (Original post by mariejuana)
ok
SO i have
n(n-1)(n-2)!/ 2(n-2)!
Would it be correct to simplify it like so
n(n-1)!/2!
and could this be further simplified ?

This is not correct.
11. (Original post by mariejuana)
ok
SO i have
n(n-1)(n-2)!/ 2(n-2)!
Would it be correct to simplify it like so
n(n-1)!/2!
and could this be further simplified ?
One factor is common to both the numerator and denominator, so it can be removed.
n(n-1)(n-2)!/ 2(n-2)!

and remember this is the same as:
n(n-1)((n-2)!)/ 2((n-2)!)

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