Tính nhanh: 1,-1/2+1/4+2/8-11/77 2,2/5+5/4+(-2/5+5/4)-5/2
2 câu trả lời
1,
-12+14+28-1177
=-24+14+14-17
=-24+(14+14)-17
=-24+24-17
=0-17
=-17
2,
25+54+(-25+54)-52
=25+54-25+54-52
=(25-25)+(54+54)-52
=0+52-52
=0+(52-52)
=0
1)-12+14+28-1177
=(-12+14)+28-1177
=((-1).22.2+14)+28-1177
=(-24+14)+28-1177
=(-14+28)-1177
=((-1).24.2+28)-1177
=(-28+28)-1177
=0-1177
=-1177
2)25+54+(-25+54)-52
=25+54-25+54-52
=(25-25)+54+54-52
=0+54+54-52
=(54+54)-52
=104-52
=52-52
`= 0