Question

chứng minh rằng 

a) abba chia hết cho 11

b) aaabbb chia hết cho 37

 

Answer 1

a,

abba=a1000+b100+b10+a1

=a(1000+1)+b(10+100)

=a.1001+b.110

=a.(11.91)+(11.10) chia hết cho 11

 

Answer 2

a,abba= 1000a + 100b + 10b+a = 1001a + 110b = 11.(91a+10b)

=> abba chia hết cho 11

b, aaabbb=111 x a x 1000+111 x b=37 x (3 x a x 1000) + 37 x (3 x b)

=> aaabbb chia hết cho 37

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Answer 3

chung minh ab-ba chia het cho 9 voi dieu kien a>b

Answer 4

Ta có :

a) \(\overline{abba}=1000\text{a}+100b+10b+a=1001\text{a}+110b=11\left(91\text{a}+10b\right)⋮11\)

b) \(\overline{aaabbb}=100000a+10000a+1000a+100b+10b+b\)

\(=111000a+111b=37\left(3000a+3b\right)⋮37\)