$3,12x10,115-3,12:4+3,12:9+3,12:100$
=$3,12x10,115-3,12x\dfrac{1}{4}+3,12x\dfrac{1}{9}+3,12x\dfrac{1}{100}$
=$3,12x(10,115-\dfrac{1}{4}+\dfrac{1}{9}+\dfrac{1}{100})$
=$3,12x(\dfrac{1973}{200}+\dfrac{109}{900})$
=$3,12x\dfrac{719}{72}$
=$\dfrac{9347}{300}$
anh xin hay nhất nhé