# Difference Of Squares in Ruby

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

1 | ```
exercism fetch ruby difference-of-squares
``` |

# 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.

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

1 |
```
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.

In order to run the test, you can run the test file from the exercise
directory. For example, if the test suite is called
`hello_world_test.rb`

, you can run the following command:

1 |
```
ruby hello_world_test.rb
``` |

To include color from the command line:

1 |
```
ruby -r minitest/pride hello_world_test.rb
``` |

## Source

Problem 6 at Project Euler http://projecteuler.net/problem=6

## Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.