x = 7 , y = 5

ta có :xy-2x+3y=13

         xy+3y-2x=13

         y(x+3)-2x=13

         y(x+3)-2x+6-6=13

         y(x+3)-2(x+3)-6=13

         (x+3)(y-2)=13+6=19

\(\Rightarrow\left(x+3\right)\left(y-2\right)\inƯ\left(19\right)\)\(=\left(-19;19;1;-1\right)\)

Mọi người ơi , giup mình câu này với

Cho a,b€ N*, thoả mãn M=(9a+11b).(5b+11a) chia hết cho 19 . Giải thích vi sao M chia hết cho 361

để A có 4 chữ số giống nhau từ nhỏ nhất trở lên có 1111,2222,3333.dễ dàng

loại trừ 2222;3333;... và chon 1111 vì 1111=11x101 [đều là số nguyên tố ]

           Đáp Số 1111 có ước nguyên tố là 11 và 101
 

Giúp mình với

Ta có:

Ư( 10)={ -10; -5; -2; -1; 1; 2; 5; 10}.

=> 2N+ 1\(\in\){ -10; -5; -2; -1; 1; 2; 5 ; 10}.

VÌ 2N+1 chia 2 dư 1.

=> 2N+ 1\(\in\){ -5; -1; 1; 5}.

=> 2N\(\in\){ -6; -2; 0; 4}.

=> N \(\in\){ -3; -1; 0; 2}.

Vậy N\(\in\){ -3; -1; 0; 2}.

Ta có sơ đồ :

Anh hiện nay :                          |----------|----------|----------|----------|

Anh trước đây ( em hiện nay ) : |----------|----------|----------|

Em trước đây :                        |----------|----------|

Tổng số phần bằng nhau là :

        4 + 3 = 7 ( phần )

1 phần có số tuổi là :

        56 : 7 = 8 ( tuổi )

Tuổi em hiện nay là :

        8 x 3 = 24 ( tuổi )

                      Đ/S : 24 tuổi           

tuoi em = 24

cảm ơn các bạn nha

các bạn đúng rồi

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bài 4 hoàng anh lớn tuổi hơn 8>6

bài 5 tuổi hiền là 13

bài 6 tuổi của bố là 40 tuổi

bài 7 15 tuổi

bài 8,9,10tui ko kịp làm vì 11h đêm rồi

bào nào ??

Chỉ phải làm câu 3 bài 1 thôi nhé !

CChiChỉChỉ 

O3=60

O4=60

O2=120

Ht

 ko hiểu thì bảo mik nha ^^