=3/5×1/4-2/5×1/4=1/4(3/5-2/5)=1/4×1/5=1/20
3/5÷4-2/5×1/4=3/5x1/4-2/5x1/4=(3/5-2/5)x1/4=1/5x1/4=1/20
3/5÷4-2/5×1/4=3/5×1/4-2/5×1/4=(3/5-2/5)×1/4=1/5×1/4=1/20