they should be hinged where you can fold the two sides closer to each other

Adjust the individual eyepieces in their relation to each other. The binocs will have a "hinge" between them to allow for adjustment for closer or farther set eyes.

Binoculars are adjustable. The double picture you see is caused by the width or distance between the lenses being wider or narrower than the distance between centres of your eyes. Adjust the width until you see a single focus point. Otherwise you are just looking at it cross eyed.

If you are using these for Astronomy, you may want to check
A quote from the following website, which specializes in binocular choosing for astronomy:

Detecting Planets With Binoculars

"One should test the binoculars before buying them. The general standard of workmanship should be good, the lenses should not be damaged and the barrels should not have dents. Now, extend the eyepieces to their full extent. Ensure that the eyepiece barrels are firm and rigid and do not tilt in any way. The focussing mechanism should run smoothly and with steady resistance. The same applies to the central pivot, which alters the spacing of the eyepieces. This should stay firmly in place once it is set.

"Most binoculars have anti-reflection coating on their object glasses. These increase contrast and improve light transmission. Ideally, all the other optical surfaces should also be coated. Look at the reflection of light in the objective lens. There will be two reflections, one from the outer surface of the objective and one from the inner surface. If both surfaces are coated, then both reflections should be coloured. By carefully adjusting the position of the binoculars one will also get reflections from the prisms inside the barrels, which indicate whether or not they are coated. Applying the same tests at the eyepiece end ensure that they are coated.

"Focus the binoculars on a point source of light and then move it towards the edge of the field of view. The point should remain in sharp focus until somewhere around two-thirds of the way out towards the edge. Binoculars with a so-called flat field should give sharp focus regardless of the position of the point within the field. Now focus the binoculars while centred on a straight line, such as the edge of a building. Inevitably, the line will appear to be bent at the edge of the field of view. Reject the binoculars if the line becomes bent more than a third of the way in from the edge. If the barrels are not set parallel to each other, the binoculars will produce a double image. Look through the binoculars while opening and closing your eyes. Look carefully for a momentary double image - it will become single as your eyes adjust to compensate - and reject binoculars that display this fault."