271-[(-43)+271-(-17)]
= 271 + 43 - 271 -17
= ( 271 - 271 ) + ( 43 - 17 )
= 0 + 26
= 26
-144-[29-(+144)-(+144)]
= - 144 - 29 + 144 + 144
= ( 144 - 144 ) + ( 144 - 29 )
= 0 + 115
= 115
a) Ta có: \(271-\left[\left(-43\right)+271-\left(-17\right)\right]\)
\(=271-\left(-43+271+17\right)\)
\(=271+43-271-17\)\(=43-17=26\)
b) Ta có: \(-144-\left[29-\left(+144\right)-\left(+144\right)\right]\)
\(=-144-\left[29-144-144\right]\)
\(=-144-29+144+144\)
\(=144-29=115\)
sai hết rồi phải bằng 115
