Show that 138+7\displaystyle \frac{\sqrt{13}}{\sqrt{8}+\sqrt{7}}8+713 can be written in the form a−b\sqrt{a}-\sqrt{b}a−b, where a a\,a and b b\,b are integers.
134 exam-style questions on Edexcel AS Level Maths Algebraic Expressions, covering 1.1 Index Laws, 1.2 Expanding Brackets, 1.3 Factorising, 1.4 Negative and Fractional Indices, and 1.5 Surds. Each one has a worked solution and a mark scheme showing where the marks go.