a) 13! = 13.12.11.....5.4.3.2.1 => 13! chia hết cho 2 và 5

11! = 11.10.9.....5.4.3.2.1 =>11! chia hết cho 2 và 5

=> A chia hết cho 2 và 5

c) A = 13! - 11! = 13.12.11! - 11! = ( 13.12 - 1 ) .11! = 155. 11! chia hết cho 155

Vậy A chia hết cho 155

Phần b) và a) mk gộp vào rồi nhé. Duyệt nha bạn . Chúc bạn học tốt

Ta có:

 A = 13! -11!

    = 11!(12.13-1)

    = 11! . 155

Mà 11! chia hết cho 2, 5 nên A chia hết cho 2 và 5.

Mà 155 chia hết cho 155 nên A chia hết cho 155

A = 13! - 11! = 1 . 2 . 3 . 4 . ...... . 13 - 1 . 2 . 3 . 4 . .... . 11

                    = 1 . 2 . 3 . 4 . .... . 11 ( 12 . 13 - 1 )

                    = 1 . 2 . 3 . 4 . .... . 11 ( 156 - 1 )

                    = 1 . 2 . 3 . 4 . .... . 11 . 155

    vì tích trên có chứa thừa số 2 ; 5 ; 155

=> A chia hết cho 2 ; cho 5 ; cho 155

chúc bạn học giỏi

a) có

b) có

c) có

a) có

b) có

c) có 

k mình nha

*13! chia hết cho 2

11! chia het cho 2=>13!-11! chia hết cho 2

*13! chia het cho 5

11! chia het cho 5=>3!-11! chia het cho 5

*155=5.31

13! ko chia hết cho 5.31

11! ko chia het cho 5.31=>13!-11! ko chia het cho 155

a)A chia hết cho 2

b)A chia hết cho 5

c)A ko chia het cho 155

**** GIÙM MÌNH NHA

a) 13! = 13.12.11....5.4.3.2.1 => 13! chia hết cho 2 và 5

11! = 11.10.9....5.4.3.2.1 => 11! chia hết cho 2 và 5

=> A = 13! - 11! chia hết cho 2 và 5

c) A = 13! - 11! = 13.12.11! - 11! = (13.12 - 1) .11! = 155.11! chia hết cho 155

Vậy A chia hết cho 155

cảm ơn Trần Thị

 Loan nhé

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 \(A=13!-11!\)

\(A=11!\cdot12\cdot13-11!\)

\(A=11!\left(12\cdot13-1\right)\)

\(A=11!\cdot155\)

\(\Rightarrow\)A chia hết cho 2 ( vì trong 11! chứa thừa số 2 )

         A chia hết cho 5

         A chia hết cho 155

a)A có chia hết cho 2

b)A có chia hết cho 5

c)A có chia hết cho 155

a) có 

b) không

c) không

A=13!-11!=6187104000

a) A chia hết cho 2 vì số tận cùng của A là số 0

b) A chia hết cho 5 vì số tận cùng của A là số 0

c)A chia hết cho 2 và 5 vì số tận cùng của A là số 0

a) Có

b) Có

cc) Không 

tick đúng nha tui nghèo lắm

1)a)

gọi 3 số đó là a;a+1:a+2

ta có: a+(a+1)+(a+2)=3a+3

mà 3 chia hết cho 3 nên 3a+3 chia hết cho3 

b) goij4 số đó là a;a+1;a+2;a+3;a+4

ta có tổng sẽ là: 4a+10

mà 10 ko chia hết cho 4 nên tổng 4 số trên ko chia hết cho 4