Bài 1 : Điền vào chỗ trống để có hằng đẳng thức
a) (2x + 1)2 = b) ............. = 9x2 – . + 1
c) (4x + 1)(4x – 1) = d) ............. = x2 – 16
e) (2x + 1)3 = f) .. = x3 – . + . – 8
g) (x + 1)( . – . + ) = h) ......... = x3 – 1
i) (x + 2y)2 = j) ............... = x2 – . + 9y2
k) (x + y)(x – y) = l) ............. = 9x2 – 4y2
m) (x + y)3 = n) ..... = x3 – . + – y3
o) (x + y)(x2 – xy + y2) = p) ......... = x3 – y3
q) (3x + 4)2 = r) .............= 4x2 – . + 25
s) (2x + 3)(2x – 3) = t) ............. = 9x2 – 25
u) (x + 1)3 = v) ........ = 8x3 – . + . – 27
w) (x + 3)( – + ) = x) ......... = x3 – 64
y) = z) ...........= 4x2 – . +
Bài 2: Phân tích đa thức thành nhân tử
a) 2x3 – 4x2 + 6x b) 2x(x – 4) + 3(x – 4)
c) 3x4 – 6x3 + 9x2 d) 3x(x – 5) + 4(5 – x)
e) 4x(x – 6) – 5(6 – x) f) x2(x – 7) + 2x(7 – x)
g) x2 + 2x + 1 h) x2 – 4x + 4
i) x2 – 4 j) 4x2 – 9
k) 4x2 + 4x + 1 l) 9x2 – 6x + 1
m) 9x2 – 1 n) x4 – 1
o) (x + 1)2 – 2(x + 1) p) (x + 2)2 + 3(x + 2)
q) (x – 1)3 – (x – 1)2 r) (x – 2)3 – (x – 2)2
Bài 3 : Tìm x
a) (2x – 1)2 – (2x – 3)(2x + 3) + 3x = 4 b) x2 + 3x = 0
c) (x + 1)2 + (x + 1) = 0 d) (2x – 3)2 – (2x – 3) = 0