answer both please

Check my work Exercise 24-5 Payback period computation; even cash flows LO P1 Compute the payback period for each of these two separate investments: a. A new operating system for an existing machine is expected to cost $270,000 and have a useful life of four years. The system yields an incremental after-tax income of $77,884 each year after deducting its staight-line depreciation. The predicted salvage value of the system is $10,000, b. A machine costs $180,000, has a $14,000 salvage value, is expected to last nine years, and will generate an after-tax income of $43,000 per year after straight-line depreciation Choose Numerator: Payback Period Choose Denominator: 1 Payback Period Payback period a b Check my wor Exercise 24-7 Accounting rate of return LO P2 A machine costs $300,000 and is expected to yield an after-tax net income of $9,000 each year. Management predicts this machine has a 10-year service life and a $60,000 salvage value, and it uses straight-line depreciation Compute this machine's accounting rate of return. Choose Numerator: Accounting Rate of Retum Choose Denominator: Accounting Rate of Return Accounting rate of return