15.37*7.89-9.37*7.89+15.37*2.11-9.37*2.11怎样简算?

(15.37*7.89+15.37*2.11)-(9.37*7.89+9.37*2.11)=15.37*10-9.37*10=60

原式=（15.37-9.37）*7.89+（15.37-9.37）*2.11
=6*7.89+6.*2.11
=6*（7.89+2.11）
=6*10
=60

15.37*7.89-9.37*7.89+15.37*2.11-9.37*2.11
=15.37*(7.89+2.11)-9.37*(7.89+2.11)
=15.37*10-9.37*10
=10*(15.37-9.37)
=10*6
=60