1、墙面的面积为:10×2.8×2﹢6×2.8×2﹣6 =56﹢33.6﹣6 =83.6﹙㎡﹚ 2、买这些墙纸需要的费用为:7.5×83.6=627﹙元﹚ 3、列式为:7.5×﹙10×2.8×2﹢6×2.8×2﹣6﹚ =7.5×83.6 =627﹙元﹚ 答:买墙纸共需627元.