n=3

ok ko phải mình chứ

ta có 2n+7 chia hết cho n-2

=>2n-4+4+7 chia hết cho n-2

=>(2n-4)+11 chia hết cho n-2

=>2(n-2)+11 chia hết cho n-2

vì n-2 chia hết cho n-2 nên 2(n-2) chia hết cho n-2

=>11 chia hết cho n-2

=> n-2 thuộc Ư(11)

Mà Ư(11)={1;11} nên n-2 bằng 1 hoặc n-2 bằng 11

+Nếu n-2=1

            n=1+2=3

+Nếu n-2=11

            n=1+2=13

                       Vậy n thuộc {3;13}

Giải:

a,

A = {0; 5; 10; 15; 20; 25; 30; 35; 40; 45; 50; ...}

B = {0; 10; 20; 30; 40; 50; ...}

=> A ∩ B = {0; 10; 20; 30; 40; 50; ...}

Phần còn lại làm tương tự.

số 4 nhé bạn vì Ư(3)={-1;1;-2;2;-4;4}

số đó là 60 nha bạn

ước là 1,2,3,4,5,6,10,12,15,20,30,60

26 điểm

giai thich ro rang cho to nha

0,000026 m³ bn nhé

26cm³ = 0,000026m³​

\(\left|-120\right|+45-31-75\)

\(=120+45-31-75\)

\(=59\)

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