Đáp án:
Giải thích các bước giải:
`a,1125-(374+1125)+(-65+374)`
`=1125-374-1125+(-65)+374`
`=[1125-1125]-[374+374]-65`
`=0-0-65`
`=-65`
`b, -23.63+23.21-58.23`
` =23.(-63+21-58)`
` =23.(-100)`
` =-2300`
` c, -2003+(-21+75+2003)`
`=-2003+2003-21+75`
`=0-21+75`
`=54`
`d,942-2567+2563-1942`
`=(942-1942)-(2567-2563)`
`=-1000-4`
`=-1004`
`e,12-12+11+10-9+8-7+5-4+3+2-1`
`=0+(11-1)-(11+10)-(9-8)-(7-5)-(4-3)+(2-1)`
`=21-1-2+1`
`=(21-1)-(1+2-1)`
`=20-2`
`=18`