()×4×9 2.5×(1.9+1.9+1.9+1.9) 3.64÷4+4.36×25%
2005× (9)÷()
142857÷117+285714÷117+571428÷117.
()×4×9 2.5×(1.9+1.9+1.9+1.9) 3.64÷4+4.36×25%
2005× (9)÷()
142857÷117+285714÷117+571428÷117.