Which conditional and its converse form a true biconditional?

a) if x> 0, then lxl > 0
b) if x=3, then x2^2=9
c) if x^2 =4, then x=2
d) if x=19, then 2x-3=35

in if you ask questions, the points are taken from your total and given to the one who answered it..

so if i have 30 points and i ask a question for 5 points, then when someone asks a question i will lose 5 points and the answerer earns 5

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