Bài 3: Tìm x
a) (2x+3)2−4x2=10
b) (x+1)2−(2+x)(x−2)=0
c) (5x−1)(1+5x)=25x2−7x+15
d) (4−x)2−16=0
e) 3x2−12x=0
g) x2−8x−3x+24=0

Bài 2: Phân tích đa thức thành nhân tử
a) x2−xy+5y−25
b) xy−y2−3x+3y
c) x2(x−3)−4x+12
d) 2a(x+y)−x−y
e) 2x−4+5x2−10x
g) 10ax−5ay−2x+y
h) a2−2a+1−b2

a) x(4x+3y)−(y−2x)2
b) (3+x)(x−3)−(x−1)(x2−3)
c)−2(x−3)2+(x+1)(5x−1)
d) (2x+1)(4x2−2x+1)−3x2(x−2)
e) (3x2+19x+20):(3x+4)
f) (7x2+x3+12x−6):(x2+4x−3)