99.66×6+66.78×18=33.22x3x6+66.78x18=(33.22+66.78)x18=100x18=1800
99.66×6+66.78×18=33.22*3*6+66.78*18=18*(33.22+66.78)=18*100=1800
99.66×6+66.78×18=99.66÷3×18+66.78×18=33.22×18+66.78×18=(33.22+66.78)×18=100×18=1800