Question

因式分解难题

X2-xy-2y2-x+5y-2 3x2+5xy-2y2+x+9y-4
这俩题怎么做

Answer 1

X2-xy-2y2-x+5y-2
=(x-2y)(x+y)-x+5y-2
=(x-2y+1)(x+y-2)

3x2+5xy-2y2+x+9y-4
=(3x-y)(x+2y)+x+9y-4
=(3x-y+4)(x+2y-1)

Answer 2

X2-xy-2y2-x+5y-2
=(x-2y)(x+y)-x+5y-2
=(x-2y+1)(x+y-2)
(x-2y) 1
(x+y) -2

3x2+5xy-2y2+x+9y-4

=(3x-y)(x+2y)+x+9y-4
=(3x-y+4)(x+2y-1)
(3x-y) -1
(x+2y) 2

Answer 3

X2-xy-2y2-x+5y-2
=(x-2y)(x+y)+(-x+5y)-2
=(x-2y+1)(x+y-2)

3x²+5xy-2y²+x+9y-4

=(3x-y)(x+2y)+x+9y-4
=(3x-y)(x+2y)-(3x-y)+4x+8y-4
=(3x-y)(x+2y-1)+4(x+2y-1)
=(3x-y+4)(x+2y-1)

Answer 4

X2-xy-2y2-x+5y-2
=(x-2y+1)(x+y-2)

3x2+5xy-2y2+x+9y-4

=(3x-y+4)(x+2y-1)