Răspuns :
[tex]3 \frac{1}{10} -1 \frac{2}{5} = \frac{31}{10}- \frac{7}{5} = \frac{31-14}{10} = \frac{17}{10}=1,7 [/tex]
3 si 1/10 -1 si 2/5 = 31/10 - 7/5 = 31/10 - 14/10 = 17/10 = 1 si 7/10 sau 1,7