Question

Сократите дробь (расписать подробно):
$\frac{2^{n+2}-2^{n-2} }{2^{n}}$

Answer 1

$\frac{2 ^{n+2} -2 ^{n-2} }{2 ^{n} } = \frac{2 ^{n-2}(2 ^{4} -1) }{2 ^{n} }= \frac{2 ^{n}*2 ^{-2}*15 }{2 ^{n} } = \frac{15}{2 ^{2} } = \frac{15}{4}=3,75$