As long as there are no numbers after them the zeros on the right of the decimal don't matter (i.e. 6.3000000=6.3 3.00000=3)
So 81.9=81.90=81.900
Since three of them are the same number there is only one answer left (81.91)
4.

5.

doesn't belong with the other three because it is irrational number
The other three can be expressed as a ratio between two <span>integers.

</span>
Answer:
the answer is 8.5
Step-by-step explanation:
divide 85 by 10 to get 8.5 for all the dimension
Answer:
Perimeter: 2l+2w
Area: lw
Step-by-step explanation:
Let l=length, and w=width
Answer:
21
Step-by-step explanation:
Idk