Question

因式分解x2-y2-z2-2yz+1-2x x2-6xy-10x+30 y+25

Answer 1

x2-y2-z2-2yz+1-2x

=x^2-2x+1-(y^2+2yz+z^2)

=(x-1)^2-(y+z)^2

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

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

x2-6xy-10x+30 y+25

=x^2-10x+25-6xy+30y

=(x-5)^2-6y(x-5)

=(x-5)(x-5-6y)

=(x-5)(x-6y-5)