设 ab=x,cd=y,ab+cd=x+y=z.有100x+y=z²z²-100(z-y)-y=0z²-100z+99y=0z=[100±√(100²-4×99y)]/2=50±√(50²-99y)∵z为整数,所以可设整数d=√(50²-99y),平方整理得99y=50²-d...