3/11*6.81 +2.19*10又3/11 +9÷1又3/8
=3/11*6.81+2.19*3/11+2.19*10+9*8/11
=3/11*(6.81+2.19)+21.9+9*8/11
=3/11*9+8/11*9+21.9
=9*(3/11+8/11)+21.9
=9+21.9
=30.9
3/11*6.81 +2.19*10又3/11 +9÷1又3/8
=3/11*6.81+2.19*3/11+2.19*10+9*8/11
=3/11*(6.81+2.19)+21.9+9*8/11
=3/11*9+8/11*9+21.9
=9*(3/11+8/11)+21.9
=9+21.9
=30.9