①1.1+0.12-0.08
②1.1-0.12+0.08
③1.1+(0.12-0.08)
④1.1-(0.12+0.08)
①3.6﹣2.8+7.4﹣7.2
②1.25×1.6×25
③÷4
④÷[(﹣)×]