Equations

Almost every real decision that involves an unknown amount hides an equation. How much of each ingredient goes into a mixture, where a shop's costs and income break even, how high a thrown object rises, how to split a bill fairly — each one becomes a solvable equation once you write it down. In this lesson you take the simple equations you already know and push them three steps further: equations tangled up in fractions, pairs of equations with two unknowns, and equations where the unknown is squared. Master these and you hold the core algebra your whole O/L paper leans on.