te rog frumos ajutor

Salut,
[tex]2^{-1}+2^{-2}=\dfrac{1}{2}+\dfrac{1}{2^2}=\dfrac{1}{2}+\dfrac{1}{4}=\dfrac{2\cdot 1+1}{4}=\dfrac{3}{4}=\dfrac{3\cdot 25}{4\cdot 25}=\dfrac{75}{100}=0,75.[/tex]
A fost greu ?
Green eyes.