Question

Phân tích đa thức thành nhân tữ.

a, 1 - 2y + y2

^b, ( x + 1)² - 25

c, 1- 4x²

d, 27 + 27x + 9x²

e, 8x³- 13x^2y + 6xy² - y³

f, 3x^2 -6 xy + 9y²

g, x² + 4x + 3

h, x² - 4x - 5

 

 

Answer 1

\(1-2y+y^2=\left(1-y\right)^2\)

\(\left(x+1\right)^2-25=\left(x+1-5\right)\left(x+1+5\right)=\left(x-4\right)\left(x+6\right)\)

\(1-4x^2=\left(1-2x\right)\left(1+2x\right)\)

\(27+27x+9x^2=9\left(3+3x+x^2\right)\)

\(8x^3-12x^2y+6xy^2-y^3=\left(2x-y\right)^3\)

\(3x^2-6xy+9y^2=3\left(x^2-2xy+3y^2\right)\)

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

\(x^2-4x-5=x^2+x-5x-5=x\left(x+1\right)-5\left(x+1\right)=\left(x-5\right)\left(x+1\right)\)

Answer 2

a ) \(1-2y+y^2=y^2-2y+1=\left(y-1\right)^2\)

b ) \(\left(x+1\right)^2-25=\left(x+1-5\right)\left(x+1+5\right)=\left(x-4\right)\left(x+6\right).\)

c ) \(1-4x^2=\left(1-2x\right)\left(1+2x\right).\)

d ) \(27+27x+9x^2=9\left(3+3x+x\right)=9\left(3+4x\right).\)

e ) \(8x^3-12x^2y+6xy^2-y^3=\left(2x-y\right)^3\)

f ) \(3x^2-6xy+9y^2=3\left(x^2-2xy+3y^2\right).\)

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

h ) \(x^2-4x-5=x^2+x-5x-5=\left(x-5\right)\left(x+1\right).\)

Answer 3

Tks

Answer 4

a, 1 - 2y + y2

= y² -2y + 1

= (y -1)²

b, ( x + 1)2 - 25

= (x + 1)² - 5²

⁼ (x + 1 - 5)(x + 1 + 5)

= (x - 4)(x + 6)

c, 1- 4x2

= (1- 2x)(1 + 2x)

d, 27 + 27x + 9x2

= 9(x² + 3x + 3)