已知:m*m+m-11=0;
则 m*m*m+m*m-11*m=0
即 m*m*m=11*m-m*m
则 m*m*m+12*m*m-21
= 11*m-m*m+12*m*m-21
= 11*m+11*m*m-21
= 11*(m*m+m)-21
= 11*(m*m+m-11)+11*11-21
= 100
已知:m*m+m-11=0;
则 m*m*m+m*m-11*m=0
即 m*m*m=11*m-m*m
则 m*m*m+12*m*m-21
= 11*m-m*m+12*m*m-21
= 11*m+11*m*m-21
= 11*(m*m+m)-21
= 11*(m*m+m-11)+11*11-21
= 100