Addition and subtraction of mathematical integral Manager Li has a mobile phone and a PHS. When paying the phone bill in October, manager Li found that the cost of mobile phone is 1.8 times that of PHS. In order to control and reduce the phone bill, manager Li decided to take certain measures. It is estimated that the cost of mobile phone will be reduced by 40% in November and that of PHS will be increased by 30%. Do you think manager Li's measures are feasible? Explain the reasons

Addition and subtraction of mathematical integral Manager Li has a mobile phone and a PHS. When paying the phone bill in October, manager Li found that the cost of mobile phone is 1.8 times that of PHS. In order to control and reduce the phone bill, manager Li decided to take certain measures. It is estimated that the cost of mobile phone will be reduced by 40% in November and that of PHS will be increased by 30%. Do you think manager Li's measures are feasible? Explain the reasons

It's very simple. As long as the price of PHS is 1, the mobile phone is 1.8, and then use the money of PHS × 1.3, the money of mobile phone × 0.6, plus, and compare with the total expenditure in October

Addition and subtraction of mathematical integral
Three teams planted trees. The first team planted a tree, the second team planted 8 more than twice of the first team, and the third team planted 6 less than half of the second team. How many trees were planted by the three teams? When a = 100, find the total number of trees planted by the three teams

The number of trees planted by the first team is 2A + 8, the number of trees planted by the third team is (2a + 8) △ 2-6 = A-2. The number of trees planted by the third team is a + (2a + 8) + (A-2) = 4A + 6. When a = 100, 4A + 6 = 406