Tính hợp lý a) 5/8 + 3/17 + 4/18 + 20/-17 + -2/9 + 21/56 b) -2/11
Giải thích
a) 58+317+418+20−17+−29+2156
=58+317+29+−2017+−29+38=58+38+317+−2017+29+−29=1+−1+0=0
b) −211+67+12+−911+17
=−211+−911+67+17=−1+1=0
a) 58+317+418+20−17+−29+2156
=58+317+29+−2017+−29+38=58+38+317+−2017+29+−29=1+−1+0=0
b) −211+67+12+−911+17
=−211+−911+67+17=−1+1=0