Students write the simplest algebraic expressions for the lengths and area of parts of a composite shape, then solve these expressions using substitution. They then solve an equation that relates an algebraic expression to a given side length.
Students interpret a graph of taxi company charges to show which company is cheaper and complete a rule for each company's charges. They also identify the distance at which each company charges the same amount.
Students use substitution to calculate the cost and length of time taken to repair washing machines, and formulate and solve a related linear equation.