Phân tích đa thức thành nhân tử
\(x^4+2019x^2+2018x+2019\)
Phân tích đa thức sau thanh nhân tử
x4+2019x2+2018x+2019
\(x^4+2019x^2+2018x+2019\)
\(=x^4-x^3+x^3+2019x^2-x^2+x^2+2019x-x+2019\)
\(=\left(x^4-x^3+2019x^2\right)+\left(x^3-x^2+2019x\right)+\left(x^2-x+2019\right)\)
\(=x^2\left(x^2-x+2019\right)+x\left(x^2-x+2019\right)+\left(x^2-x+2019\right)\)
\(=\left(x^2+x+1\right)\left(x^2-x+2019\right)\)
Phân tích đa thức thành nhân tử
a) \(4x^2-12xy+5x^2\)
b) \(\left(x+y+2z\right)^2+\left(x+y-z\right)^2-9z^2\)
c) \(x^4+2019x^2+2018x+2019\)
toán lớp một mà mình lớp 5 ko giải đc :v
phân tích đa thức thành nhân tử
a) \(x^4+2019x^2+2018x+2019\)
b) \(\left(x-y\right)^3+\left(y-z\right)^3+\left(z-x\right)^3\)
a, =x4-x + 2019x2+2019x+2019
=x(x3-1)+2019(x2+x+1)
=x(x-1)(x2+x+1)+2019(x2+x+1)
=(x2-x+2019)(x2+x+1)
b, =(x-y+y-z)[(x-y)2-(x-y)(y-z)+(y-z)2 ] + (z-x)3
=(x-z)(x2-2xy+y2-xy+xz+y2-yz+y2-2yz+z2) - (x-z)3
=(x-z)(x2-2xy+y2-xy+xz+y2-yz+y2-2yz+z2-x2+2xz-z2)
=(x-z)(-3xy+3y2+3xz-3yz)
=3(x-z)(-xy+y2+xz-yz)
=3(x-z)[(-xy+xz)+(y2-yz)]
=3(x-z)[-x(y-z)+y(y-z)]
=3(y-x)(x-z)(y-z)
Phân tích các đa thức sau thành nhân tử:
a) \(x^5+x+1\)
b) \(x^4+2019x^2+2018x+2019\)
c) \(\left(x^2-2x+4\right)\left(x^2+3x+4\right)-14x^2\)
d) \(\left(a+b+c\right)^3-a^3-b^3-c^3\)
a)pt thành đa tử : x^4+2019x^2 +2018x+2019
b)tìm giá trị nhỏ nhất của E=2x^2-8x+1
a) \(x^4+2019x^2+2018x+2019\)
\(=\left(x^4-x\right)+\left(2019x^2+2019x+2019\right)\)
\(=x\left(x^3-1\right)+2019\left(x^2+x+1\right)\)
\(=x\left(x-1\right)\left(x^2+x+1\right)+2019\left(x^2+x+1\right)\)
\(=\left(x^2+x+1\right)\left[x\left(x-1\right)+2019\right]\)
\(=\left(x^2+x+1\right)\left(x^2-x+2019\right)\)
b) \(E=2x^2-8x+1=2x^2-8x+8-7\)
\(=2\left(x^2-4x+4\right)-7=2\left(x-2\right)^2-7\)
Vì \(2\left(x-2\right)^2\ge0\forall x\Rightarrow E\ge-7\)
Dấu "=" xảy ra <=> \(2\left(x-2\right)^2=0\Leftrightarrow x-2=0\Leftrightarrow x=2\)
Vậy MinE = -7 <=> x = 2
b) \(E=2x^2-8x+1\)
\(E=2\left(x^2-4x+\frac{1}{2}\right)\)
\(E=2\left(x^2-2\cdot x\cdot2+2^2+\frac{7}{2}\right)\)
\(E=2\left[\left(x-2\right)^2+\frac{7}{2}\right]\)
\(E=2\left(x-2\right)^2+7\ge7\forall x\)
Dấu "=" xảy ra \(\Leftrightarrow x-2=0\Leftrightarrow x=2\)
Vậy....
phân tích đa thức thành nhân tử: x4+ 2018x2+2017x+ 2018
tìm x,y thuộc Z: x3+ 2x2+3x+2 = y
Ta có : x4 + 2018x2 + 2017x + 2018
= x4 - x + 2018x2 + 2018x + 2018
= x(x3 - 1) + 2018(x2 + x + 1)
= x(x - 1)(x2 + x + 1) + 2018(x2 + x + 1)
= (x2 + x + 1)(x2 - x + 2018)
Phân tích đa thức thành nhân tử:
a) x3-6x2-x-30
b) 27x3-27x2+18x-4
c) x4+2020+2019x+2020
thử dùng hệ số bất định xem thanh niên
ở đây ko cho cop link, lên mạng xem thử ik~
phân tích đa thức thành nhân tử
x4+2019x2+2018x+2019
\(=x^4-x+2019x^2+2019x+2019\)
\(=x\left(x^3-1\right)+2019\left(x^2+x+1\right)\)
\(=x\left(x-1\right)\left(x^2+x+1\right)+2019\left(x^2+x+1\right)\)
\(=\left(x^2-x\right)\left(x^2+x+1\right)+2019\left(x^2+x+1\right)\)
\(=\left(x^2-x+2019\right)\left(x^2+x+1\right)\)
\(x^4+2019x^2+2018x+2019\)
\(=\left(x^4-x\right)+\left(2019x^2+2019x+2019\right)\)
\(=x\left(x^3-1\right)+2019\left(x^2+x+1\right)\)
\(=x\left(x-1\right)\left(x^2+x+1\right)+2019\left(x^2+x+1\right)\)
\(=\left(x^2+x+1\right)\left[x\left(x-1\right)+2019\right]\)
\(=\left(x^2+x+1\right)\left(x^2-x+2019\right)\)
x4+2019x2+2018x+2019
=x4−x+2019x2+2019x+2019
=x(x3−1)+2019(x2+x+1)
=x(x−1)(x2+x+1)+2019(x2+x+1)
=(x2−x)(x2+x+1)+2019(x2+x+1)
Phân tích đa thức thành nhân tử
a) 4x^16+81
b) x^4+2018x^2+2017x+2018
\(\text{a) }4x^{16}+81=4x^4+36x^2+81-36x^8\)
\(=\left(4x^{16}+36x^8+81\right)-36x^8\)
\(=\left[\left(2x^8\right)^2+2.2x^8.9+9^2\right]+\left(6x^4\right)^2\)
\(=\left(2x^8+9\right)^2-\left(6x^4\right)^2\)
\(=\left(2x^8+9-6x^4\right)\left(2x^8+9+6x^4\right)\)
\(\text{b) }x^4+2018x^2+2017x+2018\)
\(=x^4+2018x^2+2018x-x+2018\)
\(=\left(x^4-x\right)+\left(2018x^2+2018x+2018\right)\)
\(=x\left(x^3-1\right)-2018\left(x^2+x+1\right)\)
\(=x\left(x-1\right)\left(x^2+x+1\right)+2018\left(x^2+x+1\right)\)
\(=\left(x^2-x\right)\left(x^2+x+1\right)+2018\left(x^2+x+1\right)\)
\(=\left(x^2+x+1\right)\left(x^2-x+2018\right)\)