74x57十42X74十74=74X(57十74十1)=74X122=9028
74×57+42×74+74=74×(57+42+1)=74×100=7400
74*57+42*74+74=74*(57+42+1)=74*100=7400
=74x(57+42+1)=74x100=7400
74×57+42×74+74=(57+42+1)×74=100×74=7400