有浓度为2.5%的盐水700克,为了制成浓度为3.5%的盐水,从中要蒸发掉 克水.
÷40==0.375=9÷ =.
÷5== (填小数)=15÷ .
8÷ ==0.125= %.
12÷ =9.6: == %= 成= (小数)
===12÷ = (小数)