ƚ R e .  &@ & MathTypeSymbol ؟ww wu f-2 ":y2 :y2 :y2 =y2 +y2 =y2 +yTimes New Roman؟ww wu f-2  7y2 8y2 6y2 8y2 4y2 3yTimes New Roman؟ww wu f-2 yy2 xy2 yy2 xy & "Systemu f !-