Bài 6: Viết các đa thức từ dạng tổng thành dạng tích: a) x2 + 1 + 2x = .......................................... = .................................. = .................................... b) 1 + y2 – 2y = .......................................... = .................................. = .................................... c) – 4z + z2 + 4 = ....................................... = .................................. = .................................... d) c2 + 25 – 10c = ...................................... = .................................. = .................................... e) 6xy + 9y2 + x2 = .................................... = .................................. = .................................... f) – x2 + 2xy – y2 = ................................... = .................................. = .................................... g) 12ab + 4a2 + 9b2 = ................................. = .................................. = .................................... h) – z2 – t2 + 2zt = ...................................... = .................................. = .................................... Bài 7: Viết các đa thức sau từ dạng tổng sang dạng tích a) (x + 1)2 – 2(x + 1) + 1 = ............................................................ = ............................ = ............. b) (y – 1)2 + 2(y – 1) + 1 = ............................................................ = ............................ = ............. c) (z + 2)2 – 4(z + 2) + 4 = ............................................................ = ............................ = ............. d) (a – 3)2 + 6(a – 3) + 9 = ............................................................. = ............................ = ............. e) (b2 + 5)2 – 10(b2 + 5) + 25 = ..................................................... = ............................ = ............. f) (2x + 3)2 – 4x(2x + 3) + 4x2 = .................................................. = ........................... = ............. g) (x + y)2 – 2y(x + y) + y2 = ......................................................... = ............................ = ............ h) (2x + 3)2 + 2(2x + 3)(x – 3) + (x – 3)2 = ................................... ………. .................. . ................ ………………………………………………………………………………………………….. i) (x+ 1)2 + 2(x + 1)(x – 1) + (x – 1)2 = ....................................... ………. .................. . ................ ………………………………………………………………………………………………….. j) (3x + 5)2 – 2(3x + 5)(2x – 5) + (2x – 5)2 = ............................... ………. .................. . ................ ………………………………………………………………………………………………….. k) (x+ y + 1)2 – 2(x + y + 1)(x + y) + (x + y)2 = ........................... ………. .................. . ................ ………………………………………………………………………………………………….. l) (a + b – c)2 + 2(a + b – c)(c – b) + (b – c)2 = ............................ ………. .................. . ................ ………………………………………………………………………………………………….. m) (3x – 5z)2 + 2(4z – 3x)(3x – 5z) + (4z – 3x)2 = ......................... ………. .................. . ................ ………………………………………………………………………………………………….. n) (x2 + 2x + 2)2 – 2(x2 + 2x + 2) + 1 = ......................................... = ............................ = ............. o) (x2 + 2xy)2 + 2y(x2 + 2xy) + y2 = .............................................. = ............................ = ............. Bài 11: Khai triển các hằng đẳng thức đáng nhớ sau: a) (2x + 1)3 = b) (3x + 2)3 = c) (4x + y)3 = d) (x + 5y)3 = e) (2a + 3b)3 = f) (5y + 4z)3 = g) (2x – a)3 = h) (3x – 6y)3 = i) (2a – 7b)3 = j) (7 – 5a)3 = k) (5x – 7a)3 = l) (3x – 6z)3 = Bài 12: Khai triển các hằng đẳng thức đáng nhớ sau: a) (x2 + 1)3 = b) (y2 + 3x)3 = c) (z2 + 4y)3 = d) (a3 + b2)3 = e) (4ax2 + 5b2y)3 = f) (2x3 – y2)3 = g) (x2 – 5z4)3 = h) (z5 – 3c3)3 = i) (2m3 – n5)3 = j) (5c2 – 7d2)3 = Helpppppp với mọi người ko t toang mất