Question

因式分解 2x2+xy-y2-4x+5y-6 x2-y2+a2-b2+2ax+2by 3x2+5xy-2y2+x+9y-

Answer 1

2x2+xy-y2-4x+5y-6

=(2x-y)(x+y)-4x+5y-6

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

x2-y2+a2-b2+2ax+2by

=(x-a)²-(y-b)²

=(x-a-y+b)(x-a+y-b)

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

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

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

b4-2b2-8

=(b²-4)(b²+2)

=(b-2)(b+2)(b²+2)