Question

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Answer 1

72/8 = 9
n/5=9
n=9*5
n=45

2nd one
cross multiply and get 4n=18*9
4n=162
n=162/4
n=(81/2) or 40.5 depending on if it needs to be a fraction or decimal

Answer 2

$\frac{n}{5} = \frac{72}{8} \\ \\ \frac{n}{5} = 9 \\ \\ n = 9 \times 5 \\ \\ n = 45$

The final result is: n = 45.

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$\frac{9}{n} = \frac{4}{18} \\ \\ \frac{9}{n} = \frac{2}{9} \\ \\ 9 = \frac{2}{9} n \\ \\ 9 = \frac{2n}{9} \\ \\ 9 \times 9 = 2n \\ \\ 81 = 2n \\ \\ \frac{81}{2} = n \\ \\ n = \frac{81}{2}$

The final result is: n = 81/2 or n = 40.5.