Question

x2-3xy-10y2-x+8y-2 因式分解啊

还有求证：若三角形的垂心和重心重合，则该三角形为正三角形

Answer 1

x2-3xy-10y2-x+8y-2
=(x-5y)(x+2y)-x+8y-2
=(x-5y+1)(x+2y-2)

Answer 2

分解后应该是(x-5y+1)(x+2y-2)
过程如下：
x2-3xy-10y2-x+8y-2
=(x-5y)(x+2y) -x+8y -2
=(x-5y+1)(x+2y-2)

Answer 3

x2-3xy-10y2-x+8y-2
=(x-5y)(x+2y)-x+8y-2
=(x-5y+1)(x+2y-2)