Question

Factorise
a) 10 factorial + 7 factorial

Answer 1

@ganeshie8

Answer 2

where are you stuck ?

Answer 3

frm the beginning
hw shld i start

Answer 4

whats the definition of `factorial` of a number ?

Answer 5

Product..

Answer 6

in some sense, `factorial` is just a lazy way of writing product of consecutive integers

Answer 7

\[\large 5!\]

is same as :

\[\large 5\times 4\times 3\times 2\times 1\]

Answer 8

ok

Answer 9

\[\large 3!\]

is same as :

\[\large 3\times 2\times 1\]

Answer 10

can you expand \(10!\) based on above patterns ?

Answer 11

mmm why we need to factorize something already simple O.O ?!

Answer 12

10x9x8x7x6x5x4x3x2x1

Answer 13

correct! expand \(\large 7!\) also

Answer 14

7x6x5x4x3x2x1

Answer 15

guess the teacher wants to give him some practice on factorials @ikram002p :)

Answer 16

I'm just doing revision..

Answer 17

[(10)(9)(8)+1](7!)

Answer 18

@Eyth has it !
10! = 10x9x8x7x6x5x4x3x2x1
7! = 7x6x5x4x3x2x1

see any common stuff between 10! and 7! ?

Answer 19

10! = 10x9x8x `7x6x5x4x3x2x1`
7! = ` 7x6x5x4x3x2x1`

Answer 20

ok..

Answer 21

Thanks hahaha :) Youre great!

Answer 22

common stuff is just \(7!\) right ?

Answer 23

yes

Answer 24

10! = 10x9x8x `7x6x5x4x3x2x1`
7! = `7x6x5x4x3x2x1`


can be writen as :

10! = 10x9x8x `7!`
7! = `7!`

Answer 25

add them both and factor that common stuff :

10! = 10x9x8x `7!`
7! = `7!`
--------------------------
10! + 7! = ?

Answer 26

the given answer is
11(9factorial)

Answer 27

ohk... then i guess we're only half done :
10! = 10x9x8x `7!`
7! = `7!`
--------------------------
10! + 7! = 10x9x8x `7!` + `7!`
= `7!` (10x9x8 + 1)

Answer 28

does that look okay, so far ?

Answer 29

ys

Answer 30

what's nxt

Answer 31

thinking...

Answer 32

Alright, there seems to be a typo in the given expression, it should be :

a) 10 factorial + \(\color{red}{9}\) factorial

can you check the question again ?

Answer 33

yeah it cant be 11( 9! )
mm

Answer 34

I had re-check..
There is'nt any typo

Answer 35

Try this
@xapproachesinfinity

Answer 36

So far i found only what ganesh and eyth found!
if there no typo that means we need to rewrite this 7!(721)

Answer 37

Okay @xapproachesinfinity

Answer 38

let me try and see

Answer 39

7!(6!+1) nothing you can achieve here. there must be a typo!

Answer 40

ganeshie8 is right there must be a typo

Answer 41

Yeah no doubt!