解答：1.75/2.5*0.25=1.75*0.25/2.5=1.75*（0.25/2.5）=1.75*0.1=0.175
1.75÷2.5×0.25=1.75×0.25÷2.5=1.78×（0.25÷2.5）=1.78×0.1=0.178
1.75÷2.5x0.25=1.75x（0.25÷2.5）=1.75x0.1=0.175
