x^4+2x^3+6x-9 Phân tích đa thức thành nhân tử
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\(x^4+2x^3-6x-9\)
\(=x^4-9+2x^3-6x\)
\(=\left(x^2-3\right)\left(x^2+3\right)+2x\left(x^2-3\right)\)
= \(\left(x^2-3\right)\left(x^2+3+2x\right)\)
Thợ Đào Mỏ Panda, mày bị điên à, không biết còn trả lời làm cái quái gì
a) x3-2x2-x+2
=x(x2-1)+2(-x2+1)
=x(x2-1)-2(x2-1)
=(x2-1)(x-2)
b)
x2+6x-y2+9
=x2+6x+9-y2
=(x+3)2-y2
=(x+3-y)(x+3+y)
\(2x^4+x^3-6x^2+x+2\)
= \(2x^4+4x^3-3x^3-6x^2+x+2\)
= \(2x^3\left(x+2\right)-3x^2\left(x+2\right)+\left(x+2\right)\)
= \(\left(x+2\right)\left(2x^3-3x^2+1\right)\)
=\(\left(x+2\right)\left(2x^3-2x^2-x^2+1\right)\)
=\(\left(x+2\right)\left(2x^2\left(x-1\right)-\left(x+1\right)\left(x-1\right)\right)\)
=\(\left(x+2\right)\left(x-1\right)\left(2x^2-x-1\right)\)
= \(\left(x+2\right)\left(x-1\right)\left(2x^2-2x+x-1\right)\)
=\(\left(x+2\right)\left(x-1\right)\left(2x\left(x-1\right)+\left(x-1\right)\right)\)
=\(\left(x+2\right)\left(2x+1\right)\left(x-1\right)^2\)
a) Áp dụng HĐT 1 thu được ( 2 x + y ) 2 .
b) Áp dụng HĐT 3 với A = 2x + l; B = x - l thu được
[(2x +1) + (x -1)] [(2x +1) - (x -1)] rút gọn thành 3x(x + 2).
c) Ta có: 9 - 6x + x 2 - y 2 = ( 3 - x ) 2 - y 2 = (3 - x - y)(3 -x + y).
d) Ta có: -(x + 2) + 3( x 2 - 4) = -{x + 2) + 3(x + 2)(x - 2)
= (x + 2) [-1 + 3(x - 2)] = (x + 2)(3x - 7).
1. \(x^3+2x^2-6x-27=\left(x-3\right)\left(x^2+5x+9\right)\)
2. \(9x^2+6x-4y^2-4y=\left(9x^2-4y^2\right)+\left(6x-4y\right)\)
\(=\left(3x-2y\right)\left(3x+2y\right)+2\left(3x-2y\right)=\left(3x-2y\right)\left(3x+2y+2\right)\)
3. \(12x^3+4x^2-27x-9=4x^2\left(3x+1\right)-9\left(3x+1\right)\)
\(=\left(3x+1\right)\left(x^2-\dfrac{9}{4}\right)=\left(x+\dfrac{1}{3}\right)\left(x+\dfrac{3}{2}\right)\left(x-\dfrac{3}{2}\right)\)
1) Ta có: \(x^3+2x^2-6x-27\)
\(=\left(x-3\right)\left(x^2+3x+9\right)+2x\left(x-3\right)\)
\(=\left(x-3\right)\left(x^2+5x+9\right)\)
2: Ta có: \(9x^2+6x-4y^2-4y\)
\(=\left(3x-2y\right)\left(3x+2y\right)+2\left(3x-2y\right)\)
\(=\left(3x-2y\right)\left(3x+2y+2\right)\)
\(=x\left(2x^2-x-6\right)\)
\(=x\left(2x^2-4x+3x-6\right)\)
\(=x\left[2x\left(x-2\right)+3\left(x-2\right)\right]\)
\(=x\left(x-2\right)\left(2x+3\right)\)
x(2x^2-x-6)
x(2x^2-4x+3x-6)
x[2x(x-2)+3(x-2)]
x(2x+3)(x-2)
2x^5-6x^4-2a^2x^3-6ax^3
=(2x^5-2a^2x^3)-(6x^4+6ax^3)
=2x^3(x^2-a^2)-6x^3(x+a)
=2x^3(x-a)(x+a)-6x^3(x+a)
=(x+a)(2x^4-2x^3a-6x^3)
=(x+a) 2x^3 (x-a-3)
\(=x^4-x^3+3x^3-3x^2+3x^2-3x+9x-9\\ =\left(x-1\right)\left(x^3+3x^2+3x+9\right)\\ =\left(x-1\right)\left(x+3\right)\left(x^2+3\right)\)
\(x^4+2x^3+6x-9=x^3\left(x-1\right)+3x^2\left(x-1\right)+3x\left(x-1\right)+9\left(x-1\right)\)
\(=\left(x-1\right)\left(x^3+3x^2+3x+9\right)\)
\(=\left(x-1\right)\left[x^2\left(x+3\right)+3\left(x+3\right)\right]\)
\(=\left(x-1\right)\left(x+3\right)\left(x^2+3\right)\)