I'm trying to make a program similar to this example:

Hi! Let's calculate a slope. We will need two points (x1, yl) and (x2, y2) Let's prompt you for both, then calculate the slope. Please enter x1: 56.78 Please enter y1: 22.2 Please enter x2: 33.3 Please enter y2: 44.4 The slope is: -0.9454855195911412 Isn't learning fun?practice mini assignement 2.py - C:/Users/kmf62/AppData/Local/Programs/Python/Python39/practice mini assignement 2.py (3.9... 0 X IDLE Shell 3.9.1 0 X File Edit Format Run Options Window Help File Edit Shell Debug Options Window Help print ("Welcome to my Mini-Project 3! Today I will be solving a simple linear equation.") Python 3.9.1 (tags/v3. 9.1: le5d33e, Dec 7 2020, 17:08:21) [MSC v. 1927 64 bit (AM print ("To beging I will be assigning my variables with coefficients)") D64) ] on win32 print ("Lets plug in some numbers and solve an equation!") Type "help", "copyright", "credits" or "license ()" for more information. = float (input ("Please enter a: ") ) > > > b = float (input ("Please enter b:" = RESTART: C:/Users/kmf62/AppData/Local/Programs/Python/Python39/practice mini a c = float (input ("Please enter c: ssignement 2. py d = float (input ("Please enter d: ") ) Welcome to my Mini-Project 3! Today I will be solving a simple linear equation. To beging I will be assigning my variables with coefficients) #assign variables with coefficients (a, b, c,d) to get a simple linear equation Lets plug in some numbers and solve an equation! #and display calculated simple linear equation Please enter a: 19.5 print (f"The Simple Lineary Equation is: ", equation (a, b, c, d) ) Please enter b: 11 print ("Simple Linear Equations are so simple!") Please enter c: 24.9 Please enter d: 1.34 Traceback (most recent call last) : File "C:/Users/kmf62/AppData/Local/Programs/Python/Python39/practice mini assi gnement 2.py", line 11, in print (f"The Simple Lineary Equation is: ", equation (a, b, c, d) ) NameError: name 'equation' is not defined > > > Ln: 3 Col: 57 Ln: 16 Col: 4