7.3x3.7_7.3+0.73x73=7.3x3.7_7.3+7.3x7.3=7.3(3.7_1+7.3=7.3x10=73。
=7.3×3.7-7.3+7.3×7.3=7.3×(3.7-1+7.3)=7.3×10=73
