Question

2x的平方加4xy加2y的平方减x减y减1

因式分解5x的平方加(9加a)x加2a减2

Answer 1

解法如图:

诀窍：1.第一题在第二步开始可以把(x+y)当成一个整体然后十字相乘

望采纳，谢谢！:)

Answer 2

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

5x²+(9+a)x+2a-2
=5x²+(9+a)x+2(a-1)
=(x+2)[5x+(a-1)]
=(x+2)(5x+a-1)