ƚ  K n .   &4 & MathTypep-5@5\55 5B5Times New Roman؟ww w f - 2 hwrong 2 $wrong 2 @wrong2 1xr2 4xr2 yr2 uxr2 lxrTimes New Roman؟ww w f - 2  2 $ 2 3 2 Y6 2 3 2 \4 2 B  2  , 2 r5 2  5 2  2 , 2 5 2 2  Times New Roman؟ww w f -2 2 2 2 2 2 Symbol @؟ww w f -2 '/ 2 - 2 F/ 2 */ 2 - 2 I/ 2 / 2  / 2 - 2 q+ 2 / 2 h+ 2 / & "System  f !\-