Câu hỏi của Nguyễn Thanh Huyền

Question

bài này khó quá ạ, có ai giúp mình đc khum, cảm ưn nhìu

Nguyễn Lê Phước Thịnh · Accepted Answer

3:

$6a+11b-6\left(a+7b\right)$

$=6a+11b-6a-42b=-31b⋮31$

Ta có: $\left(6a+11b\right)-6\left(a+7b\right)⋮31$

$6a+11b⋮31$

Do đó: $6\left(a+7b\right)⋮31$

=>$a+7b⋮31$

Ta có: $\left(6a+11b\right)-6\left(a+7b\right)⋮31$

$a+7b⋮31$

Do đó: $6a+11b⋮31$

4:

$5a+2b⋮17$

=>$12\left(5a+2b\right)⋮17$

=>$60a+24b⋮17$

=>$51a+17b+9a+7b⋮17$

=>$17\left(3a+b\right)+\left(9a+7b\right)⋮17$

mà $17\left(3a+b\right)⋮17$

nên $9a+7b⋮17$

Câu trả lời:

3:

$6a+11b-6\left(a+7b\right)$

$=6a+11b-6a-42b=-31b⋮31$

Ta có: $\left(6a+11b\right)-6\left(a+7b\right)⋮31$

$6a+11b⋮31$

Do đó: $6\left(a+7b\right)⋮31$

=>$a+7b⋮31$

Ta có: $\left(6a+11b\right)-6\left(a+7b\right)⋮31$

$a+7b⋮31$

Do đó: $6a+11b⋮31$

4:

$5a+2b⋮17$

=>$12\left(5a+2b\right)⋮17$

=>$60a+24b⋮17$

=>$51a+17b+9a+7b⋮17$

=>$17\left(3a+b\right)+\left(9a+7b\right)⋮17$

mà $17\left(3a+b\right)⋮17$

nên $9a+7b⋮17$

2n - 3	-1	-5	1	5
n	1	-1	2	4