6) (36+79) +(145- 79-36) = 36 + 79 + 145 - 79 - 36
= (36-36) + (79-79) +145
= 0 + 0 + 145
= 145
7) [10-(12-(-9-1)] =10 - [( 12 - (-10)]
=10 - (12 +10)
= 10 -12 -10
= (10-10) -12 =12
8) (38 - 29 + 43)-(43+38) = 38 - 29 + 43 - 43 - 38
= ( 38 - 38) + (43 - 43) - 29
= 0 + 0 - 29
= -29
9) 271-[(-43)+271- (-17)] = 271 -(-43 +271 +17)
= 271 +43 -271 -17
= (271-271) +43 -17
=26
10) -144-129-(+144)-(+144)] = -144 -129 -144 -144
= (-144).3 -129
= -432 -129 = -561
Câu 10 ko tính nhanh đc bn!!!