# Difference Of Squares

Find the difference between the square of the sum and the sum of the squares of the first N natural numbers.

The square of the sum of the first ten natural numbers is
(1 + 2 + ... + 10)² = 55² = 3025.

The sum of the squares of the first ten natural numbers is
1² + 2² + ... + 10² = 385.

Hence the difference between the square of the sum of the first
ten natural numbers and the sum of the squares of the first ten
natural numbers is 3025 - 385 = 2640.

* * * *

For installation and learning resources, refer to the
[exercism help page](http://exercism.io/languages/ruby).

For running the tests provided, you will need the Minitest gem. Open a
terminal window and run the following command to install minitest:

    gem install minitest

If you would like color output, you can `require 'minitest/pride'` in
the test file, or note the alternative instruction, below, for running
the test file.

Run the tests from the exercise directory using the following command:

    ruby difference_of_squares_test.rb

To include color from the command line:

    ruby -r minitest/pride difference_of_squares_test.rb


## Source

Problem 6 at Project Euler [http://projecteuler.net/problem=6](http://projecteuler.net/problem=6)

## Submitting Incomplete Solutions
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