(1)希望小学四月份水电费480元,五月份的水电费比四月份节约了15%.五月份水电费是多少元?
(2)希望小学五月份水电费408元,比四月份节约了15%.四月份水电费是多少元?
(1)480×(1-15%)
=480×85%
=408(元)
答:五月份水电费是408元.
(2)408÷(1-15%)
=408÷85%
=480(元)
答:四月份水电费是480元.
(1)希望小学四月份水电费480元,五月份的水电费比四月份节约了15%.五月份水电费是多少元?
(2)希望小学五月份水电费408元,比四月份节约了15%.四月份水电费是多少元?
(1)480×(1-15%)
=480×85%
=408(元)
答:五月份水电费是408元.
(2)408÷(1-15%)
=408÷85%
=480(元)
答:四月份水电费是480元.