Does it mater which term goes first in a ratio, explain

Yes it all depends on the question if it says there is 12 potatos and 5 tomatos what is the ratio of tomatos to potatos you have to make sure you put tomatos first

Yes, the first term applies to the the first term in the statement, so for example,

'The ratio of apples to oranges in the box is 2:5'

The 2 applies to the apples, and the 5 applies to the oranges.

If the question was misread, it could be interpreted as 5 apples to 2 oranges, which is wrong.