Tính: c) [ 3/5 + ( − 1/4 ) ] : 3/7 + [ ( − 3/4 ) + 2/5 ] : 3/7 ;
Giải thích
c) [35+(−14)]:37+[(−34)+25]:37
=[35+(−14)] . 73+[(−34)+25] . 73
=[35+(−14)+(−34)+25] . 73
=[(35+25)+(−14+−34)] . 73
=[1+(−1)] . 73=0 . 73=0
c) [35+(−14)]:37+[(−34)+25]:37
=[35+(−14)] . 73+[(−34)+25] . 73
=[35+(−14)+(−34)+25] . 73
=[(35+25)+(−14+−34)] . 73
=[1+(−1)] . 73=0 . 73=0