GCSE · Surds

Simplifying surdsExam-style questions

Why surds are kept as exact values, why √(ab) = √a × √b lets you pull square factors out, and how to collect like surds — and why √a + √b is not √(a+b).

11 questions · GCSE (Higher) level · mark scheme and worked solution on each · no sign-up to try

DifficultyAllLevel 3Level 4Level 5
  1. 1
    Simplify fully 200+18−50\sqrt{200} + \sqrt{18} - \sqrt{50}.
    Level 4 · 3 marksTry it
  2. 2
    Simplify fully 38−18+23\sqrt{8} - \sqrt{18} + \sqrt{2}.
    Level 4 · 3 marksTry it
  3. 3
    (a) Write 180\sqrt{180} in the form a5a\sqrt{5}, where aa is an integer.

    (b) Hence, or otherwise, work out 1805\dfrac{\sqrt{180}}{\sqrt{5}}.
    Level 4 · 3 marksTry it