Chapter Summary

Algebraic concepts

• Letters represent unknowns, generalised numbers, or variables.
• An expression has terms but no equals sign. A linear expression has at most the first power of the variable.

Key operations

• Like terms (same variable, same power) can be combined: $ax + bx = (a + b)x$.
• Expansion (distributive law): $a(b + c) = ab + ac$.
• Factorisation (reverse of expansion): $ab + ac = a(b + c)$.
• For algebraic fractions, find the LCM before combining.
• Always verify: expand to check factorisation, substitute to check simplification.