Задача Задача №3696003
А
А
\[ \begin{aligned} 400+(51-21)-1&=429;\\ 400+51-(21-1)&=431;\\ 5550-2220+(80+20)&=3430;\\ 5550-(2220+30)+20&=3320. \end{aligned} \]
\[ \begin{aligned} 400+(51-21)-1&=429;\\ 400+51-(21-1)&=431;\\ 5550-2220+(80+20)&=3430;\\ 5550-(2220+30)+20&=3320. \end{aligned} \]
