How do you simplify $(20!)/(17!)$ ?

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Answer 1 · 2018-04-30T01:34:39

Given: $(20!)/(17!)$

Substitute $20! =17!(18)(19)(20)$

$(20!)/(17!) = (17!(18)(19)(20))/(17!)$

Cancel the two factorials:

$(20!)/(17!) = (18)(19)(20)$

Multiply the 3 numbers:

$(20!)/(17!) = 6840$

Answer 2 · 2018-06-24T20:27:18

$6840$

Let's just expand this out:

$(20*19*18*17...)/(17!)$

We notice that the continuation of $20!$ starting with $17$ cancels with the denominator of $17!$ .

$(20*19*18*cancel(17...))/cancel(17!)$

This leaves us with

$20*19*18$

$=>360*19=6840$

Hope this helps!

How do you simplify (20!)/(17!)(20!)/(17!)?