Answer:
Let's say that the class has a total of 7x students, where 2x wear glasses and 5x don't.
After 5 of the students who didn't wear glasses now do, the number of students who don't wear glasses becomes 5x - 5.
So, the new ratio of students who wear glasses to those who don't wear glasses is:
2x : (5x - 5)
We can simplify this ratio by dividing both terms by the greatest common factor, which is x:
2 : (5 - 5/x)
We can't simplify this any further, but we can see that the ratio is not fixed and depends on the value of x.