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Mathematics 18 Online
OpenStudy (anonymous):

9 Combination 2

OpenStudy (anonymous):

@Nnesha

Nnesha (nnesha):

same formula

OpenStudy (anonymous):

\[\frac{ 9! }{ 2! (9-2)! }\]

Nnesha (nnesha):

looks good

OpenStudy (anonymous):

\[\frac{ 9*8*7*6*5*4*3*2*1 }{ 2*1 (7)! }\]

Nnesha (nnesha):

that's right but here is a shortcut \[\huge\rm \frac{ 9 · 8 · 7! }{ 2!(7)! } =\] there is 7! at the misdemeanor so you can expand 9! to 7! so you cancel them out then we don't need a calculator

OpenStudy (anonymous):

but then wouldnt it just be 9*8

Nnesha (nnesha):

\[\huge\rm \frac{ 9 · 8 ·\cancel{7!} }{ 2!\cancel{(7)!} } =\]

Nnesha (nnesha):

yes right

Nnesha (nnesha):

but don't forget the 2! at the denominator

OpenStudy (anonymous):

then 2 goes into 8 2 times and 8/2=4 so 9*4=36?

Nnesha (nnesha):

right

OpenStudy (anonymous):

k thx

Nnesha (nnesha):

np :=)

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