Answer:
starting with least...
-1.6
-6/5
-7/8
9/10
5/2
...to greatest.
Explanation:
start by putting the decimals into fractions:
-1.6 = -8/5
0.9 = 9/10
and then find a common denominator to compare them fairly.
the number that they all end up going into is 40, which will be your common demoninator.
-8/5 (aka -1.6) = -64/40
5/2 = 100/40
-7/8 = -35/40
9/10 (aka 0.9) = 36/40
-6/5 = -48/40