Phân tích thành nhân tử:
A) x^2-x-30
B) x^2+x-42
Phân tích đa thức thành nhân tử:
a) (x+2)² + 2(x²-4) + (x-2)²
b) x² - x + ¼
c) (x+y)³ - (x-y)³
`a)(x+2)^2+2(x^2-4)+(x-2)^2`
`=(x+2)^2+2(x-2)(x+2)+(x-2)^2`
`=(x+2+x-2)^2=(2x)^2=4x^2`
`b)x^2-x+1/4`
`=x^2-2.x .1/2+1/4=(x-1/2)^2`
`c)(x+y)^3-(x-y)^3`
`=(x+y-x+y)[(x+y)^2+(x+y)(x-y)+(x-y)^2]`
`=2y(x^2+2xy+y^2+x^2-y^2+x^2-2xy+y^2)`
`=2y(3x^2+y^2)`
a) \(\left(x+2\right)^2+2\left(x^2-4\right)+\left(x-2\right)^2\)
\(=\left(x+2\right)^2+2\left(x+2\right)\left(x-2\right)+\left(x-2\right)^2\)
\(=\left(x+2+x-2\right)^2=\left(2x\right)^2=4x^2\)
b) \(x^2-x+\dfrac{1}{4}=\left(x-\dfrac{1}{2}\right)^2\)
c) \(\left(x+y\right)^3-\left(x-y\right)^3=\left(x^3+3x^2y+3xy^2+y^3\right)-\left(x^3-3x^2y+3xy^2-y^3\right)=6x^2y+2y^3=2y\left(3x^2+y^2\right)\)
a)(x+2)2+2(x2−4)+(x−2)2a)(x+2)2+2(x2-4)+(x-2)2
=(x+2)2+2(x−2)(x+2)+(x−2)2
=(x+2)2+2(x-2)(x+2)+(x-2)2
=(x+2+x−2)2=(2x)2=4x2
=(x+2+x-2)2=(2x)2=4x2
b)x2−x+14b)x2-x+14
=x2−2.x.12+14
=(x−12)2=x2-2.x.12+14
=(x-12)2
c)(x+y)3−(x−y)3c)(x+y)3-(x-y)3
=(x+y−x+y)[(x+y)2+(x+y)(x−y)+(x−y)2]
=(x+y-x+y)[(x+y)2+(x+y)(x-y)+(x-y)2]
=2y(x2+2xy+y2+x2−y2+x2−2xy+y2)
=2y(x2+2xy+y2+x2-y2+x2-2xy+y2)
=2y(3x2+y2)
Phân tích thành nhân tử:
a) 2x-2√x
b)x-√x -6
c)4x -4√x +1
\(a,2x-2\sqrt{x}=2\sqrt{x}\left(\sqrt{x}-1\right)\\ b,x-\sqrt{x}-6=x-3\sqrt{x}+2\sqrt{x}-6\\ =\sqrt{x}\left(\sqrt{x}-3\right)+2\left(\sqrt{x}-3\right)=\left(\sqrt{x}-3\right)\left(\sqrt{x}+2\right)\\ c,4x-4\sqrt{x}+1=\left(2\sqrt{x}\right)^2-2.2\sqrt{x}.1+1^2=\left(2\sqrt{x}+1\right)^2\)
a) \(2x-2\sqrt{x}=2\sqrt{x}\left(\sqrt{x}-1\right)\)
b) \(x-\sqrt{x}-6=\left(\sqrt{x}-3\right)\left(\sqrt{x}+2\right)\)
c) \(4x-4\sqrt{x}+1=\left(2\sqrt{x}-1\right)^2\)
Phân tích đa thức thành nhân tử:
a) (x+1)(x+2)(x+3)(x+4)-15
b) ((2x+5)^2)-(x-9)^2
a) \(\left(x+1\right)\left(x+2\right)\left(x+3\right)\left(x+4\right)-15\left(1\right)=\left[\left(x+1\right)\left(x+4\right)\right]\left[\left(x+2\right)\left(x+3\right)\right]-15=\left(x^2+5x+4\right)\left(x^2+5x+6\right)-15\)
Đặt \(t=x^2+5x+4\)
(1) trở thành: \(t\left(t+2\right)-15=t^2+2t+1-16=\left(t+1\right)^2-4^2=\left(t-3\right)\left(t+5\right)\)
Thay t: \(\left(x+1\right)\left(x+2\right)\left(x+3\right)\left(x+4\right)-15=\left(x^2+5x+4-3\right)\left(x^2+5x+4+5\right)=\left(x^2+5x+1\right)\left(x^2+5x+9\right)\)
b) \(\left(2x+5\right)^2-\left(x-9\right)^2=\left(2x+5-x+9\right)\left(2x+5+x-9\right)=\left(x+14\right)\left(3x-4\right)\)
a: Ta có: \(\left(x+1\right)\cdot\left(x+2\right)\left(x+3\right)\left(x+4\right)-15\)
\(=\left(x^2+5x+4\right)\left(x^2+5x+6\right)-15\)
\(=\left(x^2+5x\right)^2+10\left(x^2+5x\right)+24-15\)
\(=\left(x^2+5x\right)^2+10\left(x^2+5x\right)+9\)
\(=\left(x^2+5x+1\right)\left(x^2+5x+9\right)\)
b: \(\left(2x+5\right)^2-\left(x-9\right)^2\)
\(=\left(2x+5-x+9\right)\left(2x+5+x-9\right)\)
\(=\left(x+15\right)\left(3x-4\right)\)
phân tích đa thức thành nhân tử:a, x^2(x+1)-2x(x+1)+x+1b, 4x^2 - 8x +3
a) \(x^2 (x+1)-2x(x+1)+x+1 \\ =(x+1)(x^2-2x+1)\\=(x+1)(x-1)^2\)
b) \(4x^2 -8x+3 \\= (2x^2)-2.2x .2 + 2^2 -1 \\=(2x-2)^2-1^2\\=(2x-2+1)(2x-2-1)\\= (2x-1)(2x-3)\)
Phân tích đa thành nhân tử:
a)x(x3-4)+2x3-4
b) (1+2x)(1-2x)-x(x+2)(x-2)
a: \(x\left(x^3-4\right)+2x^3-4\)
\(=x^4-4x+2x^3-4\)
\(=\left(x^2-2\right)\left(x^2+2\right)-2x\left(x^2+2\right)\)
\(=\left(x^2+2\right)\left(x^2-2x-2\right)\)
b: \(\left(1+2x\right)\left(1-2x\right)-x\left(x+2\right)\left(x-2\right)\)
\(=1-4x^2-x\left(x^2-4\right)\)
\(=1-4x^2-x^3+4x\)
\(=-\left(x^3-1+4x^2-4x\right)\)
\(=-\left[\left(x-1\right)\left(x^2+x+1\right)+4x\left(x-1\right)\right]\)
\(=-\left(x-1\right)\left(x^2+5x+1\right)\)
phân tích đa thức thành nhân tử:A=(x-1)(x+2)(x-3)(x+4)-144
Bn ấn vào câu hỏi của bn sẽ rs những câu tương tự có đáp án nhé!!Chúc bn lm đc bài này nha!!
Trả lời:
A=(x-1)(x+2)(x-3)(x+4)-144
A= (x2-5x-14)(x2-5x-24)-144 (1)
đặt m=x2-5x-14
=> A= m.(m-10)-144
A=m2-10m-144
A= (m-18)(m+8)
thay m vào, ta có:
A= (x2-5x-32)(x2-5x-6)
A=(x2-5x-32)(x+1)(x-6)
Phân tích đa thức thành nhân tử:
a)x.(x-1)+(1-x)^2
b)(x+1)^2-3.(x+1)
c)2x.(x-2)-(x-2)^2
a) \(x\left(x-1\right)+\left(1-x\right)^2\)
\(=x\left(x-1\right)+\left(x-1\right)^2\)
\(=\left(x-1\right)\left(x+x-1\right)\)
\(=\left(x-1\right)\left(2x-1\right)\)
b) \(\left(x+1\right)^2-3\left(x+1\right)\)
\(=\left(x+1\right)\left[\left(x+1\right)-3\right]\)
\(=\left(x+1\right)\left(x+1-3\right)\)
\(=\left(x+1\right)\left(x-2\right)\)
c) \(2x\left(x-2\right)-\left(x-2\right)^2\)
\(=\left(x-2\right)\left[2x-\left(x-2\right)\right]\)
\(=\left(x-2\right)\left(2x-x+2\right)\)
\(=\left(x-2\right)\left(x+2\right)\)
Phân tích các đa thức sau thành nhân tử:
a, 5ax – 10ay
b, x^2 – xy + x – y
c)x^2 - 8x + 7
a: \(=5a\left(x-2y\right)\)
b: \(=x\left(x-y\right)+\left(x-y\right)=\left(x-y\right)\left(x+1\right)\)
c: =(x-1)(x-7)
a)\(5ax-10ay=5a\left(x-2y\right)\)
b) \(x^2-xy+x-y=x\left(x-y\right)+\left(x-y\right)=\left(x+1\right)\left(x-y\right)\)
c) \(x^2-8x+7=\left(x-7\right)\left(x-1\right)\)
a)5a(x-2y)
b)\(\left(x^2+x\right)-\left(xy+y\right)\)
\(x\left(x+1\right)-y\left(x=1\right)\)
\(\left(x+1\right)\left(x-y\right)\)
c)\(x^2-x-7x+7\)
\(x\left(x-1\right)-7\left(x-1\right)\)
\(\left(x-1\right)\left(x-7\right)\)
Phân tích thành nhân tử:
a) \(x^2-ax+5x-5a\)
b) \(x^3-4x^2+4x\)
c) \(x^2-2x-y^2+1\)
\(a,x^2-ax+5x-5a=x\left(x-a\right)+5\left(x-a\right)=\left(x-a\right)\left(x+5\right)\\ b,x^3-4x^2+4x=x\left(x^2-4x+4\right)=x\left(x-2\right)^2\\ c,x^2-2x-y^2+1=\left(x^2-2x+1\right)-y^2=\left(x-1\right)^2-y^2=\left(x-y-1\right)\left(x+y-1\right)\)
Hãy phân tích thành nhân tử:
a) \(x^2-y^2-6x+9\)
a) (x2-6x+9)-y2=(x-3)2-y2=(x-3-y)(x-3+y)