Is subtraction associative

Yes, because theres parenthesis around each problem.

is wrong because if there wasn't parenthesis

example 2-3-4= -5

then mix it up

example 3-4-2= -3

so it is not

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Subtraction is NOT associative.

Consider 2 - 3 - 4

2 - (3 - 4) = 2 - (-1) = 2 + 1 = 3

(2 - 3) - 4 = -1 - 4 = -5