Question

please please solve this question

Answer 1

take LCM and do cross multiplication and you will get the answer n to be 36

Answer 2

$\frac{n}{2} - \frac{3n}{4} + \frac{5n}{6} = 21 \\ n( \frac{6 - 9 + 10}{12} ) = 21 \\ n = \frac{21 \times 12}{7} \\ n = 36$
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