八年级上册的因式分解6个小小滴计算题

Question

1: (x+a)²-（y+b)²
2: 25(a+b)²-4(a-b)²
3: 18a²-50
4: a四次方-16
5: 1/2p²-2pq
6: a²(a-3)-a+3
急急急~~~
谢谢了

Answer 1

1:(x+a+y+b)(x+a-y-b)
2:(7a+3b)(3a+7b)
3:2(3a+5)(3a-5)
4:(a²+4)（a²-4)
5:

Answer 2

1:(x+a+y+b)(x+a-y-b)
2:(7a+3b)(3a+7b)
3:2(3a+5)(3a-5)