[tex]2^{20}*0,5^9=2^{20}*(\frac{1}{2} )^9 = (\frac{1}{2})^{-20} * (\frac{1}{2})^9=(\frac{1}{2})^{-20+9} = (\frac{1}{2}) ^{-11} = 2^{11}= 2048[/tex]
