You can
put this solution on YOUR website!fist simplify the factorials
7! is the same thing as 7*6*5*4*3*2*1
5! is the same as 5*4*3*2*1
2! is the same as 2*1
therefore the 5! will cancel out 7! and be left with 7*6 divided by 2*1
the answer will be
21
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