-2003 +(-21+75+2003)
= -2003 -21+75+2003
= (2003-2003) + (75-21)
= 0 + 54
= 54
1152 + (374+1152) + (-65 +374)
= 1152 + 374+1152 -65 +374
= (1152+1152)+(374+374) - 65
= 1152.2 + 374.2 - 65
= 2304 + 748 - 65
= 3052 - 65
= 2987
Câu 1:
-2003 +(-21+75+2003)
= -2003 + (-21) + 75 + 2003
= (-2003+2003) + (-21) + 75
= 0 + (-21) + 75
= 54
Câu 2:
1152 + (374+1152) + (-65 +374)
= 1152 + 374 + 1152 + 374+ (-65)
= 1526 + 1526 + (-65)
= 3052 + (-65)
= 2987
-2003 +(-21+75+2003)
= -2003 -21+75+2003
= (2003-2003) + (75-21)
= 0 + 54
= 54
1152 + (374+1152) + (-65 +374)
= 1152 + 374+1152 -65 +374
= (1152+1152)+(374+374) - 65
= 1152.2 + 374.2 - 65
= 2304 + 748 - 65
= 3052 - 65
= 2987
\(-2003+\left(-21+75+2003\right)\)
\(=-2003-21+75+2003\)
\(=\left(-2003+2003\right)+\left(75-21\right)\)
\(=0+54\)
\(=54\)
\(1152+\left(374+1152\right)+\left(-65+374\right)\)
\(=1152+374+1152-65+374\)
\(=2.1152+2.374-65\)
\(=2\left(1152-374\right)-65\)
\(=2.778-65\)
\(=1556-65\)
\(=1491\)