Modelling with Linear Relationships
Solving simultaneous equations: Solution by substitution (Cycling puzzle part 3)

Modelling with Linear Relationships

Linear Algebra Skills

• Finding the gradient between coordinates
• Graphing linear equations (slope-intercept form)
• Graphing linear equations (general form)
• Vertical and horizontal lines
• Finding equations of linear graphs in slope-intercept form (part 1)
• Finding equations of linear graphs in slope-intercept form (part 2)
• Finding equations of linear graphs in general form

Solving Simultaneous Equations (Cycling Puzzle Series)

• Introduction (Cycling Puzzle Part 1)
• Graphical solution (Cycling Puzzle Part 2)
• Solution by substitution (Cycling Puzzle Part 3)
• ​Solution by elimination (Cycling Puzzle Part 4)​

The Feasible Region (Fete Stall Series)

• Introduction (Fete Stall Part 1)
• Graphing the feasible region (Fete Stall Part 2)​
• Defining the feasible region (Fete Stall Part 3)
• Setting up additional constraints (Fete Stall Part 4)

​​Linear Programming Skills

• Constructing constraints
• Graphing constraints
• Finding the optimal solution
• Considering Wastage
• Dealing with Discrete Only Solutions

We will now consider some algebraic methods for solving simultaneous equations.
The method of solution by substitution is used when at least one equation is given with either x or y as the subject of the formula. We substitute an expression for this variable into another equation.