what evidence is there that Rip’s encounter with the men in the mountains was not just part of a dream that he had when he fell asleep while hunting in the mountains?

There is no concrete evidence that Rip's encounter with the men in the mountains was part of his dream when he fell asleep while hunting in the mountains.

From the text, Rip is described as falling asleep and waking to hear a stranger call his name. It is possible that his encounter with the men on the mountains could be a dream.  

Explanation:

Irving Washington's Rip Van Winkle is a short story about an easygoing man Rip Van Winkle who is a likable man but has to endure his wife's constant nagging and because of this, he leaves home often to avoid her.

He is a hardworking man who can hunt and fish but has bad luck with his farmland as it refused to yield produce.

He spends most of his time at the inn with other idle men but his wife still follows him there and nags him and the other men so he goes into the woods to hunt, with his dog Wolf and gun.

One day Rip goes high into the mountains to hunt squirrels, he gets tired and falls asleep. When he wakes, he hears a strange voice calling his name and he helps him carry his keg up a hill where he sees strange-looking men on Dutch clothes and he eventually has a drink with them and falls asleep.

When he wakes, he discovers that the men are no longer there, his beard is now a foot long, his gun is old and rusty and Wolf, his dog is no longer there.  

the answer is something i don't know

substitute y = 2x - 4 to x + 2y = 12:

x + 2(2x - 4) = 12     use distributive property

x + (2)(2x) + () = 12

x + 4x - 8 = 12     add 8 to both sides

5x = 20     divide both sides by 5

x = 4

put the value of x to the first equation:

y = 2(4) - 4

y = 8 - 4

y = 4