(2 điểm)

A a) x = 3, c) x = ± √6, d) (-1; 1)

B a) x = 5 hoặc x = 3, c) x = ± √6, d) (1; -1)

C a) x = 3, c) x = ± √3, d) (1; -1)

D a) x = 3, c) x = ± √3, d) (-1; -1)