Perform the indicated operations and explain .

you need to give us more information since we can't answer

i dont know

step-by-step explanation:

the reason i dont know is because i have not taken this class and for that reason i haven't learned this stuff

hope i could

on the middle line

step-by-step explanation:

1/5=50

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