3] Consider the sums of the first even integers: 2+42+4+62+4+6+8=== What do you notice? (Try to write the result as a product in each case.) Now let us find a general formula for the sum of the first n even numbers: 2+4+6+8+10++2n=?? (Note: Even if you did not "guess" the result from the examples, you can calculate the sum directly, as we did for the odd numbers in the practice sectionl) Show all the work here