Question

Answer 1

b)

Xét \(\overline{2014xy}=201400+\overline{xy}\)

= 201396 + 4 + \(\overline{xy}\)

Để \(\overline{2014xy}⋮12\)

<=> \(\overline{xy}+4⋮12\)

\(\overline{xy}+4\)	12	24	36	48	60	72	84	96
\(\overline{xy}\)	08	20	32	44	56	68	80	92

 

 

 

Answer 2

a)

\(7x+4y⋮37\)

<=> \(14\left(7x+4y\right)⋮37\)

<=> \(98x+56y⋮37\)

<=> \(111x-13x+74y-18y⋮37\)

Mà \(111x⋮37;74y⋮37\)

<=> \(13x+18y⋮37\)