Question

solve it
${2}^{n} + {2}^{n - 1} \div {2}^{n + 1} - {2}^{n}$

Answer 1

${2}^{n} + {2}^{n - 1} \div {2}^{n + 1} - {2}^{n} \\ \\ = {2}^{n} + {2}^{(n - 1 - n - 1)} - {2}^{n} \\ \\ = {2}^{ - 2} \\ \\ = { (\frac{1}{2} )}^{2} \\ \\ = \frac{1}{4}$