Tính: a) 2763 + 152; b) (–7) + (–14) c) (–35) + (–9).

* Hướng dẫn giải

a) 2763 + 152 = 2915

b) Ta có : |–7| = 7; |–14| = 14.

Do đó: (–7) + (–14) = – ( |–7| + |–14| ) = – (7 + 14) = –21.

c) (–35) + (–9) = – (|–35| + |–9|) = – (35 + 9) = –44.