Having learned to manipulate expressions and polynomials, we are ready to solve equations: to find the value of the unknown that makes an equality true. The heart of the chapter is the two principles of equivalence, the tools that let us “move” terms from one side to the other without altering the solutions. From here we tackle fractional equations (with the unknown in the denominator and their existence conditions), literal or parametric equations (which require a discussion as the parameters vary) and finally a rich gallery of word problems — ages, motion, mixtures, tanks, percentages, distributions — all reducible to a single linear equation.
Sections
- Principles of equivalence
- Fractional equations
- Literal (parametric) equations
- Problems solvable with first-degree equations