PRD for ES3_HW_4

1. Used an arrow function that takes an array of numbers and returns the sum and the difference of the first two elements in the array.
2. Consoled it.
3. Extracted the first and last characters from a string using an arrow function and consoled it.
4. Calculated area of rectangle. extracted length and width from a rectangle object and consoled it.
5. Used an arrow function that takes an object with a nested object and extracts information from it.
6. Used an array of numbers and returns the product of first two numbers and then subtract the third number from it.
7. Created an arrow function that takes an object extracts information from it.
8. Called and consoled all an arrow function.