a) (27+514)-(486-73)
=27+514-486+73
=541-486+73
=55+73
=128
b) (36+79)+(145-79-36)
=36+79+145-79-36
=115+145-79-36
=260-79-36
=181-36
=145
c) 10-[12-(-9-1)]
=10-12+(-9)+(-1)
=(-2)+(-9)+(-1)
=(-11)+(-1)
=-12
tick nha bạn
5)27+514-486+73
6)36+79+145-79-36
7)10-12-9-1
(27+514)-(486-73)
=27+514-486+73
=(27+73)-(486+514)
=100-1000
=(-10)