no excel please, equations only

7. Two methods of supplying water and sewage treatment for a housing development outside the districts where and sewage-disposal services are provided by the city are described by the accompanying cash flows for a 40-year study period: Year 0 1-10 10 11-20 20 21-30 30 31-40/yr Method 1 -$350,000 -$11,000/yr -$25,000 -$13,000/yr -$150,000 -$15,000/yr -$25,000 -$18,000/yr Method 2 -$735,000 -$8,000/yr $100,000 -$13,000/yr $100,000 -$15,000/yr -$75,000 -$15,000/yr Both methods have the same absolute cash flow amounts over the study period ($1,120,000), and both provide corporate quality of service. At an interest rate of 8%, determine which method has the lower equivalent annual cost