1.（52-14）x48 52x48-14x4852+14+48 52+（14+48）52x（14+48）52x14+52x4852x14x48 14x（48x52） 2.=80÷4 =7+4=20 =11 =720÷36=880÷80=20 =11 3.><<= 4.=(175+25)+(68+232)=200+300=500 =25x4x13=100x13=1300 =120÷(3x4)=120÷12=10 =47x(200

1.（52-14）x48 52x48-14x4852+14+48 52+（14+48）52x（14+48）52x14+52x4852x14x48 14x（48x52） 2.=80÷4 =7+4=20 =11 =720÷36=880÷80=20 =11 3.><<= 4.=(175+25)+(68+232)=200+300=500 =25x4x13=100x13=1300 =120÷(3x4)=120÷12=10 =47x(200