Phân tích đa thức thành nhân tử Dùng phương pháp đặt nhân tử chung: 4a + 4b 2a + 4b – 6c – 4a – 8b – 12c 6xy – 12x – 18y x3 - 2x –ax – ay – a 4ax – 6ay – 10 3a2x - 6a2y + 12ax 5a( x + y) + 6x( x+y) 10 7ax( +x) + 8b( x +2) 11 3xy( x- 4) – 5( –x) 12 2a2b( x + 3) – 4a3b ( -x – 3) 13 xm +2 - xm 14 2a2b + 4ab – 6ab2 15 m ( x + y ) – n ( x + y ) 16 3a ( x + y ) – 6ab ( x + y ) 17 18 19 20 21 22 23 24 -2ab ( x – y ) – 4a ( x – y ) m ( a – b ) – m2 ( a – b ) x(a–b)–y(b–a ) ( 2a – ) – y ( – a) ( a – ) + 8a ( – a ) 2x( y – 3) + ( – y ) ( x + 3)( x – ) + ( x + )2 ( x – )2 – 5( – x ) Dùng đẳng thức x2 + 10x + 25 x2 – 14x +49 4x2 + 12xy + 9y2 16x2 - 8x +1 4a4 +20a2 + 25 a2 - 4b2 9x2 – 1 36 x2 – 25y2 16x – 81 10 (a+b)2 - 11 (x – y)2 – 12 13 14 15 16 17 18 19 y2 – ( x +1)2 8x3 – 27 a3b3 + 64 + x6 27x3 – ( a+b)3 8a3 +12a2 +6a +1 125 – 75m + 9m2 – m3 x2 – 49 23 – 2y +y2 24 9x2 + 6xy + y2 25 x2 + 4y2 + 4xy 26 8x3 + 12x2y + 6xy2 + y3 27 27 – x3 + 9x2 – 27x 28 8x3 – 27 20 4x2 – 25y2 21 (x + y)2 – (x – y)2 22 9(x + 1)2 – 4x2 29 64a3 + 30 125x3 + Phương pháp nhóm hạng tử ax + ay + 2x + 2y x2 – xy + 3x – 3y 10ax – 5ay – 2x + y 2x2 – 6xy + 5x – 15y a –b – x(a - b) 3x – 3y + x2 – y2 4x2 + 2xy - + y x2 + 2x + – 4y2 25 9x2 – 6xy + y2 10 36y2 – 9x2 – 12x – 11 x2 – y2 + 14y – 49 12 ax2 – 5x2 - ax + 5x + a – 13 ax – bx – 2cx - 2a + 2b + 4c 14 27x2 – – 3xy + y 15 16 17 18 x3 - x2 + 4x – a2 – 4b2 + 4ax – 8xb a2 – b2 + 4a – 4b x2 – 9– 5x + 15 19 9x2 – 12xy +4 y2 –12x +8y 20 4x2 – 9y2 + 4x – 6y 21 10xy – 5y – 4x2 + 4x – 22 23 24 25 16x2 – – 24 xy + 9y2 x3 + y3–3x – 3y x2 – 9– 5x + 15 9x2 – 12xy +4y2 –12x +8y 17 18 19 20 21 22 23 a3 + 2a2 b + ab2 – 9a a4 – 4a2 + 4a – 27x2 – – 3xy + y x3 - x2 + 4x – a2 – 4b2 + 4ax – 8xb a2 – b2 + 4a – 4b a2 – 9b2 + 3a – 9b Phối hợp nhiều phương pháp 6x2 + 12xy + 6y2 2x3 + 8x2y + 8xy2 28x2 y– 28xy + 7y – 3x2 – 12x – 12 5a2 – 8x3 - 8x 3x3y3 + 24 (a + b)3 + c3 49a2 - x2 + 2x – 10 x2 + 6x + – a2 – 2ab + b2 11 – 2m + m2 – x2 – 4x – 12 ax2 + bx2 - 6ax – 6bx + 9a + 9b 13 7x2y2 – 63x2z2 14 2x2 – 8z2 15 12a3b +36 a2b2 + 9ab3 16 16x4y - 48x3y + 36x2y Thêm bớt , tách hạng tử x2 – 4x + x2 + 6x + x2 – 7x +12 x + x – 20 4x2 + 5x – 4x2 + 15x + 2x2 – 3x – 6x2 + 13x + x2 + xy - 2y2 10 3x2 + 10x + 11 x4 + 12 a4 + 64 13 14 4x + 4x − 2x + x − 15 16 17 18 4x + 16x − −5x − 29x − 20 −7x + 11x + −x + x − 19 20 21 − x + 25x − 150 −7x + 11x + 8x − 10x −