A) X2 – 4X + 4 = 25 B) 1990X −17+1986X −21+1004X+1=4C) 4X – 12

Bài 1 (3 điểm): Tìm x biết:

a) x

2

– 4x + 4 = 25

b)

1990x −17+1986x −21+1004x+1=4

c) 4

x

– 12.2

x

+ 32 = 0