translate simple situations or procedures into algebraic expressions or formulae; derive an equation (or two simultaneous equations), solve the equation(s) and interpret the solution
A21-01 [Turning Problems into Linear Equations Example 1]
A21-02 [Turning Problems into Linear Equations Example 2]
A21-03 [Turning Problems into Linear Equations Example 3]
A21-04 [Turning Problems into Linear Equations Example 4]
A21-05 [Turning Problems into Linear Equations Example 5]
A21-06 [Turning Problems into Linear Equations Example 6]