下列式子中一定成立的是() A.(a - b)2 = a2- b2 B.(a +
题型:选择题
问题:
下列式子中一定成立的是( )
A.(a - b)2 = a2- b2
B.(a + b)2 = a2 + b2
C.(a - b)2 = a2-2ab + b2
D.(-a - b)2 = a2-2ab + b2
下列式子中一定成立的是( )
A.(a - b)2 = a2- b2
B.(a + b)2 = a2 + b2
C.(a - b)2 = a2-2ab + b2
D.(-a - b)2 = a2-2ab + b2