x2-a2+2ab-b2=0.
x2-a2+2ab-b2=0
x2-(a2-2ab+b2)=0
x2-(a-b)2=0
(x+a-b)(x-a+b)=0
解得:x=b-a或x=a-b
单词拼写。
1. Could you please l_____ me your pen?
2. Could you please tell me where to p_____ my car?
3. I w_____ if you can help me.
4. I'm sorry to t_____ you.
5. The path l_____ to the forests.
9,13,18,24,31,()
A.39
B.38
C.37
D.40