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
—I can’t stop smoking, doctor. — For your health, I’m afraid you ______.
A.may
B.can
C.have to
D.need
弧坑裂纹