Question

Tính giá trị các biểu thức sau:

a) \({\left( { - 5} \right)^{ - 1}}\); 

b) \({2^0}.{\left( {\frac{1}{2}} \right)^{ - 5}}\);       

c) \({6^{ - 2}}.{\left( {\frac{1}{3}} \right)^{ - 3}}:{2^{ - 2}}\).

Answer 1

a) \(\left(-5\right)^{-1}=-\dfrac{1}{5}\)

b) \(2^0\cdot\left(\dfrac{1}{2}\right)^{-5}=1\cdot32=32\)

c) \(6^{-2}\cdot\left(\dfrac{1}{3}\right)^{-3}:2^{-2}\)

\(=\dfrac{1}{36}\cdot27:\dfrac{1}{4}\)

\(=\dfrac{27\cdot4}{36}=3\)