①x²-4x+9 ②4（x-y）²-4(y-x) ③3x(x-2)-(2-x) ④ -二分之一x的四次方+8

①x²-4x+9 ②4（x-y）²-4(y-x) ③3x(x-2)-(2-x) ④ -二分之一x的四次方+8
①x²-4x+9 ②4（x-y）²-4(y-x) ③3x(x-2)-(2-x) ④ -二分之一x的四次方+8

①x²-4x+9 ②4（x-y）²-4(y-x) ③3x(x-2)-(2-x) ④ -二分之一x的四次方+8
因式分解?
①x²-4x+9
题目可能写错了.

②4（x-y）²-4(y-x)
=4（x-y）²+4(x-y)
=4(x-y)[(x-y)+1]
=4(x-y)(x-y+1)
③3x(x-2)-(2-x)
=3x(x-2)+(x-2)
= (x-2)(3x+1)
④ -二分之一x的四次方+8
=(-1/2)(x的四次方-16)
=(-1/2)(x²+4)(x²-4)
=(-1/2)(x²+4)(x+2)(x-2)