The aim of this challenge is to write a script that allows the user to input the equation of two straight lines (Line 1: y=ax+b, Line 2: y=cx+d). The program will then calculate the coordinates of the intersection point if such a point exists!

#### Flowchart

#### Your Code

Complete your code here, using the steps described on the above flowchart.

#### Testing

Once your code is complete, you can check it works by completing the following tests:

Test # | Input Values | Expected Output | Actual Output |

#1 | a = 5 b = -10 c = -3 d = 22 |
(4,10) | |

#2 | a = 0 b = 20 c = 2 d = -50 |
(35,20) | |

#3 | a = -1 b = 0 c = 2 d = 0 |
(0,0) | |

#4 | a = 5 b = 10 c = 5 d = 30 |
Both lines are parallel |

#### Using Python Turtle to trace the lines!

The following code uses Python Turtle to trace both lines.

#### Extension Task

Can you write a computer program that takes the (x,y) coordinates of two different points and calculates the linear equation (y = ax + b) of the straight line joining these two dots.

To do so you will need to:

- Retrieve four inputs: x1, y1, x2, y2 (The coordinates of the two points to join)
- Calculate the slope of the straight line:
**a**= (y2 – y1) / (x2 – x1) - Calculate
**b**= y1 –**a**x1 - Display the linear equation: y =
**a**x +**b**

Note that in case of a vertical line (if x1 == x2), you will not be able to calculate the slope a. The equation of your straight line would then be x = x1.