问题
选择题
下列各式运用平方差公式分解因式正确的是 [ ]
A.x2+y2=(x+y)(x+y)
B.x2-y2=(x+y)(x-y)
C.-x2+y2=(-x+y)(-x-y)
D.-x2-y2=-(x+y)(x-y)
答案
答案:B
下列各式运用平方差公式分解因式正确的是 [ ]
A.x2+y2=(x+y)(x+y)
B.x2-y2=(x+y)(x-y)
C.-x2+y2=(-x+y)(-x-y)
D.-x2-y2=-(x+y)(x-y)
答案:B