问题
选择题
下列计算错误的是 [ ]
A .(x+1)(x+4)=x2+5x+4
B .(y+4)(y-5)=y2+9y-20
C .(m+2)(m-3)=m2-m-6
D .(x-3)(x-6)=x2-9x+18
答案
答案:B
下列计算错误的是 [ ]
A .(x+1)(x+4)=x2+5x+4
B .(y+4)(y-5)=y2+9y-20
C .(m+2)(m-3)=m2-m-6
D .(x-3)(x-6)=x2-9x+18
答案:B