Question

Phân tích các đa thức thành nhân tử

a, x² - z² + y² - 2xy

b, -x - y² + x² - y

3, x² - 2xy - 4z² + y²

d, x (x + y) - 5x - 5y

e, x² - 5x + 5y - y²

f, x² + 4x + 3

g, 10x ( x - y) - 8 (y - x)

h, x² - 3x + 2

Answer 1

a,x²-z²+y²-2xy

=(x²-2xy+y²)-z²

=(x-y)²-z²

b,-x-y²+x²-y

=(x²-y²)-(x+y)

=(x-y)(x+y)-(x+y)

=(x+y)(x-y-1)

c,x²-2xy-4z²+y²

=(x²-2xy+y²)-(2z)²

=(x-y)²-(2z)²

=(x-y-2z)(x-y+2z)

d,x(x+y)-5x-5y

=x(x+y)-5(x+y)

=(x+y)(x-5)

e, x² - 5x + 5y - y²

=(x²-y²)-5(x-y)

=(x+y)(x-y)-5(x+y)

=(x+y)(x-y-5)

f, x² + 4x + 3

=x²+x+3x+3

=x(x+1)+3(x+1)

=(x+1)(x+3)

g, 10x ( x - y) - 8 (y - x)

=10x(x-y)+8(x-y)

=2(x-y)(5x+4)

h, x² - 3x + 2

=x²-x-2x+2

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

=(x+1)(x-2)