Answer:
-21/10
Explanation:
-2/5 - 4/5 = -6/5 <--
a common denominator
Then...
-6/5 -9/10 = -21/10
There is not a common denominator so you have to multiply 2 to the -6/5 to make it -12/10
The answer can be left as an improper fraction which is -21/10
or a mixed number -2 1/10 th