2. |a-i|=37(in the third quadrant)

(5x-1)^2= (5x)^2-2(5x)×1+(1)^2=25x^2-10x+1

point m is on plane r

the diagram shows you   triangle def with de=4, df=9 and de≠df≠ef.

the sum of the lengths of two triangles' sides are always greater than the length of the third side:

substitute sides lengths:

then 5< ef< 13 (option 3 is true).

def is a scalene triangle with all sides of different lengths (option 5 is true, option 2 is false).

answer: correct choices are 1, 3 and 5