①4/(x² - 4) = 1/(x + 2)4/[(x + 2)(x - 2)] = 1/(x + 2)不考虑x = -2, 4/(x - 2) = 1x = 6A(0, 6), OA = 6OA : OB = 3 : 4, OB = 8题叙述不清(将△OAB沿哪条直线折叠),没法继续做。