7.3 yuan adds 1 dictionary, which is equivalent to 2 dictionaries.

The money for three dictionaries plus 7.3x3 = 2 1.9 yuan is the money for six dictionaries. ,

This can be regarded as 5+3x2 = 1 1 dictionaries.

(147.5+7.3x3) ÷ (5+3x2) =169.4 ÷1=15.4 yuan.

Every dictionary 15.4 yuan.

15.4x2-7.3 = 23.5 yuan; 23.5 yuan per dictionary.

The checking calculation15.4x5+23.5x3 = 77+70.5 =147.5 is correct! !