ax-x+ay+2y+5-2a=0

(x+y-2)a=x-2y-5

So when x+y-2=x-2y-5=0, this equation holds no matter what value A takes.

x+y-2=0

x-2y-5=0

minus

3y+3=0

y=- 1，x=3

So the common solutions are x = 3 and y =- 1.

I counted x times the first time and y times the second time.

3X+ 1≤55，5Y+2≤55 X，Y∈N

Take the maximum value of X and Y, and get X= 18 and Y= 10.

So there are 52

3 solution: (2m-n) x from the meaning of the question.

Divide both sides of Equation 4 by 3, and it is 41x+19y =177.

Y = (177-41x)/19 because Y > 0, x can only be equal to 1 2 3 4.

When x =1177-41=136 = 8 *17 is not divisible by 19.

X = 2177-41* 2 = 95 = 5 * 19 is divisible by19.

X = 3177-41* 3 = 54 = 9 * 6 is not divisible by 19.

X = 4177-41* 4 =13 is not divisible by 19.

So x=2.

5 Respondents added that 2009-08- 17 15:22 let 4 digits be abcd.

1.2 * d+2 & lt； c/2

2.a=d b=c

3.c+d= 10

Formula 1, 3

Acquisition of c & gt44/5 c can only be 9 d= 1.

A= 1 b=9, then 199 1.

The length of each side of a regular pentagonal square ABCDE is 2000/5=400 meters.

Let's assume that when A and B first walk on the same side,

Both are at the apex.

The distance difference between them is 400 meters.

And the distance difference between the two is 800 meters.

So A walked (800-400)/(50-46)= 100 minutes,

Verify that A is not at the vertex at this time.

Because at this time A walked 50 * 100 = 5000m,

5000/400= 12, and the balance is 200 (meters).

So A has to walk for another 200/50=4 minutes.

That is, 104 minutes later,

A and B walk on the same side for the first time.