đề sai hoặc x vô nghiệm

Vô đây xem: bài 1:phân tích đa thức thành nhân tửa)7x^3y-14x^2y+7xy^3b)3x^2-3xy-5x+5yc)x^2+7x+12giúp mình với  - Hoc24

=x(x^3+7x^2+14x+14+4)

=x(x^3+7x^2+14x+18)

   x⁴+7x³+14x²+14x+4

=x⁴+7x³+4x²+10x²+14x+4

=(x⁴+4x²+4)+(7x³+14x)+10x²

=(x²+2)²+7x(x²+2)+10x²

=(x²+2)²+2x(x²+2)+5x(x²+2)+10x²

=(x²+2)(x²+2+2x)+5x(x²+2+2x)

=(x²+2+2x)(x²+2+5x)

\(x^4+7x^3+14x^2+14x+4\)

\(=x^4+x^3+6x^3+6x^2+8x^2+8x+4x+4\)

\(=x^3\left(x+1\right)+6x^2\left(x+1\right)+8x\left(x+1\right)+4\left(x+1\right)\)

\(=\left(x+1\right)\left(x^3+6x^2+8x+4\right)\)

\(a,=7xy\left(x^2-2xy+y^2\right)=7xy\left(x-y\right)^2\\ b,=3x\left(x-y\right)-5\left(x-y\right)=\left(3x-5\right)\left(x-y\right)\\ c,=x^2+3x+4x+12=\left(x+3\right)\left(x+4\right)\)

b) 3x⁴-3x³+9x³-9x²-24x²+24x-48x+48

=3x³(x-1)+9x²(x-1)-24x(x-1)-48(x-1)

=(x-1)(3x³+9x²-24x-48)

=3(x-1)(x³+3x²-8x-16)

1, \(7x^2y^5-14x^3y^4-21y^3=7y^3\left(x^2y^2-2x^3y-3\right)\)

2, \(-12x^2y+6xy^2-15xy=3xy\left(-4x+2y-5\right)\)

3, \(-14x^2y-21xy^2+28x^2y^2=-7xy\left(2x+3y-4xy\right)\)

Trả lời:

1, 7x²y⁵ - 14x³y⁴ - 21y³ = 7y³ ( x²y² - 2x³y - 3 )

2,  -12x²y + 6xy² - 15xy = 3xy ( - 4x + 2y - 5 )

3, -14x²y - 21xy² + 28x²y² = 7xy ( - 2x - 3y + 4xy )