[tex] \frac{7!}{3! \times 5!} + \frac{9!}{2! \times 7!} [/tex]
[tex] = \frac{1 \times 2 \times 3 \times 4 \times 5 \times 6 \times 7}{1 \times 2 \times 3 \times 1 \times 2 \times 3 \times 4 \times 5} + \frac{1 \times 2 \times 3 \times 4 \times 5 \times 6 \times 7 \times 8 \times 9}{1 \times 2 \times 1 \times 2 \times 3 \times 4 \times 5 \times 6 \times 7} [/tex]
[tex] = \frac{6 \times 7}{1 \times 2 \times 3} + \frac{8 \times 9}{1 \times 2 } [/tex]
[tex] = \frac{42}{6} + \frac{72}{2} [/tex]
[tex] = 7 + 36[/tex]
[tex] = 43[/tex]
