1 Answer

JGilmartin · Answer 1 · 2020-05-20T12:09:50+0000

Answer:

21

Explanation:

Note that n! = n(n - 1)(n - 2) ..... × 3 × 2 × 1, thus

7! = 7 × 6 × 5 × 4 × 3 × 2 × 1

5! = 5 × 4 × 3 × 2 × 1

2! = 2 × 1

Hence

cancel 5 × 4 × 3 × 2 × 1 on numerator/ denominator, leaving

(7(6))/(2(1)) =
(42)/(2) = 21

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