华威大学tesol:初二的数学问题

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当x为何值时,(|x-3|)/(x^-9)=1/(x+3)成立。

You missed a "2":

(|x-3|)/(x^2-9)=1/(x+3)

=> |x-3|/(x+3)(x-3)= 1/(x+3)

=> x-3 = |x-3|

=> x>3