please show full working using the formula

Shaolin has decided to sell a new line of A1 smartphones, at $825 per unit and a variable cost of $370 per unit. The company has spent $150,000 for a marketing study that determined that the company will sell 74,000 A1 smartphones per year for seven years. The marketing study also determined that the company will lose sales of 8900 units per year of the previous model L2 smartphones. The L2 sell at $1250, with a variable cost of $630. The fixed costs each year will be $14,350,000.

The company has also spent $1,000,000 on research and development for the new smartphones. New plant and equipment will cost $29,400,000, and will be depreciated on a straight-line basis. The A1 smartphones will also require an increase in net working capital of $3,500,000 that will be returned at the end of the project. The tax rate is 40%, and the cost of capital is 14%.

Calculate the payback period and the NPV.