Question

Помогите пожалуйста ❤❤❤❤​

Answer 1

$\displaystyle\bf\\C_{7} ^{3}=\frac{7!}{3!\cdot(7-3)!}=\frac{4!\cdot 5\cdot 6\cdot 7}{1\cdot 2\cdot 3\cdot 4!} =5\cdot 7=35\\\\\\A_{10} ^{5} =\frac{10!}{(10-5)!} =\frac{5!\cdot 6\cdot 7\cdot 8\cdot 9\cdot 10}{5!} =6\cdot 7\cdot 8\cdot 9\cdot 10=30240\\\\\\P_{7} =7!=1\cdot 2\cdot 3\cdot 4\cdot 5\cdot6\cdot7=5040\\\\\\C_{7} ^{3} \cdot A_{10} ^{5} -9P_{7} =35\cdot 30240-9\cdot 5040=1058400-45360=1013040$

Answer 2

(7!/(3!*4!)*(10!/5!)-9*7!=(7*6*5/6)*(10*9*8*7*6)-9*5040=35*30240-45360=1058400-45360=1013040