2除3除7+4除6除14+14除21除49 ------------------------------------------ 4除7除9+8除14除18+28除49除63要过程

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2除3除7+4除6除14+14除21除49 ------------------------------------------ 4除7除9+8除14除18+28除49除63
要过程

2÷3÷7+4÷6÷14+14÷21÷49
=2÷3÷7+(2×2)÷(3×2)÷(7×2)+(2×7)÷(3×7)÷(7×7)
=2÷3÷7+(2÷3÷7)/2+(2÷3÷7)/7
=2/21×(1+1/2+1/7)
=2/21×23/14
=23/147
4÷7÷9+8÷14÷18+28÷49÷63
=4÷7÷9+(4×2)÷(7×2)÷(9×2)+(4×7)÷(7×7)÷(9×7)
=4÷7÷9+(4÷7÷9)/2+(4÷7÷9)/7
=4/63×(1+1/2+1/7)
=4/63×23/14
=46/441