41−(115+41)−[−15−(−219)]

=41−115−41−[−15+219]

=(41−41)−115+15−219

=0+(−115+15)−219

=0−100−219

=−319

Ước của 280 là: 1,2,4,5,7,8,10,28,35,40,56,70,140,280.

1) ƯCLN (140;120)=20

    ƯC(140;120)=1,2,5,10,20

2)ƯCLN(150;50)=50

   ƯC(150;50)=1,2,5,10,50

3)ƯCLN(12,20,1)=1

   ƯC(12,20,1)=1

When my mother helps me with the homework.

A có 2022 số hạng chia thành 674 nhóm.

A=(1+4+4mũ2)+......+(4mũ2019 + 4mũ2020 + 4mũ2021)

A=21+.....+4mũ2019(1+4)

A=21+...+4mũ2019.21

A=21.(1+......4mũ2019)chia hết cho 21

           Vậy A chia hết cho 21

1. A.delicious B.like C.nice D.fine 2. A. postcard B.come C.home D.so 3 A high B dish C fish D city