Question

8!/6!
7!/2!•4!
9!/6!•3!
8!-7!/6!​

Answer 1

$\frac{1 \times 2 \times 3 \times 4 \times 5 \times 6 \times 7 \times 8}{1 \times 2 \times 3 \times 4 \times 5 \times 6} = \frac{7 \times 8}{1} = 56 \\ \frac{1 \times 2 \times 3\times 4 \times 5 \times 6 \times 7}{1 \times 2 \times 1 \times 2 \times 3 \times 4} = \frac{5 \times 6 \times 7}{2} = 15 \times 7 = 105 \\ \frac{1 \times 2 \times 3 \times 4 \times 5 \times 6 \times 7 \times 8 - 1 \times 2 \times 3 \times 4 \times 5 \times 6 \times 7}{1 \times 2 \times 3 \times 4 \times 5 \times 6} = \frac{720(56 - 7)}{720} = 56 - 7 = 49$