因式分解：（m²-m）x²-(2m-1)x+m²+m 2x²-3xy-2y²+3x+4y-2 1/2x²-2x+1

第一题改了,
不然不好做

(m²-m）x²-(2m²-1)x+m²+m
=m(m-1)x²-(2m²-1)+m(m+1)
=[mx-(m+1) ]*[(m-1)x-m]

2x²-3xy-2y²+3x+4y-2
=(2x²-3xy-2y²)+(3x+4y-2)
=(2x+y)(x-2y)+2(2x+y)+2y-x-2
=(2x+y)(x-2y+2)+2y-x-2
=(x-2y+2)(2x+y-1)
1/2x²-2x+1
=1/2(x²-4x+4)-1
=1/2[(x-2)²-2]
=1/2[(x-2)+√2][(x-2)-√2]
=1/2(x-2+√2)(x-2-√2)