You can tell that a fraction is a unit fraction when it is over a unit of one. This is also known as unit rate.
Answer:
If you are doing subtraction with fractions you need to make a common denominator and subtract the numerators from each other
ex. 1/2 - 1/3
make a common denominator (or find the least common multiple)
3/6 - 2/6
subtract the numerators
take 2 from 3 and put that on top.
Solution 1/2-1/3= 3/6-2/6= 1/6
No solution bc the equations aren't equal to each other
The height should be C.) 400 mm. Hope this helps!! <3