Answer:
By "starters" what do you mean?
10
The slope of all parallel lines is equal. 10 is the slope in the equation y = 10x - 20, so the slope of a line parallel to it has to be 10 also.
A
The absolute value of -27 is 27, so it is the same number
Here is a trick that not a lot of people know
(# of terms)*(first+last)/2
(in case you don't know, * means multiply and / means divide)
