单项选择题
A.-5x+6 B.5x+6 C.-5x D.5x E.以上结论均不正确
A.(x+4)(x-7) B.(x+7)(x-4) C.(x+4Y)(x-7y) D.(x+7y)(z-4y) E.以上结果均不正确
A.1 B.1或0 C.-1 D.-1或0 E.1或-1