Repeated subtraction is a method of subtracting the equal number of items from a larger group. It is also known as division. If the same number is repeatedly subtracted from another larger number until the remainder is zero or a number smaller than the number being subtracted, we can write that in the form of division
D.) Nanometer is the smallest among your options.
It is equal to 10^-9
Hope this helps!
-1/9+-5/9=
When you are adding a negative number, the operation turns into subtraction:
-1/9-5/9=

Really, it's just subtraction. The simplest form is -2/3, which is equal to -0.66667.
I hope this helps :)