Given y=5xy = 5^xy=5x
Express 25x 25^x\,25x in terms of yyy.
Hence, or otherwise, solve 25x−22(5x)−75=025^x - 22(5^x) - 75 = 025x−22(5x)−75=0.
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.