Question

Soa sánh 1.\(\left(\dfrac{1}{2}\right)^{27}và\left(\dfrac{1}{3}\right)^{18}\) 2.\(\left(\dfrac{-4}{7}\right)^{205}và\left(\dfrac{-5}{8}\right)^{205}\) 3,\(\left(\dfrac{-1053}{2317}\right)^{2016}và\left(\dfrac{2342}{-3426}\right)^{2015}\)

Answer 1

1: \(\left(\dfrac{1}{2}\right)^{27}=\left(\dfrac{1}{8}\right)^9\)

\(\left(\dfrac{1}{3}\right)^{18}=\left(\dfrac{1}{9}\right)^9\)

mà 1/8>1/9

nên \(\left(\dfrac{1}{2}\right)^{27}>\left(\dfrac{1}{3}\right)^{18}\)

2: \(\dfrac{-4}{7}=\dfrac{-32}{56}\)

\(\dfrac{-5}{8}=\dfrac{-35}{56}\)

mà -32>-35

nên \(\dfrac{-4}{7}>\dfrac{-5}{8}\)

hay \(\left(\dfrac{-4}{7}\right)^{205}>\left(-\dfrac{5}{8}\right)^{205}\)