Answer:
Undefined
Step-by-step explanation:
has a slope of 
, since it is a horizontal line. The only types of lines that are perpendicular to horizontal lines are vertical lines, which are usually in the form 
(where 
is any real number). Vertical lines have an undefined slope, so the answer is undefined. Hope this helps!
D has the commutative property because it just flip flopped the numbers.
Answer:
point!!!!!!!
Step-by-step explanation:
Answer:
20
23 is between 20 and 30, but it's closer to 20. So 23 is rounded down to 20.
