Edexcel Gcse Maths Study Guide Graded A+

Repeated percentage change (finding money) {Ans: E.g. 4% compound interest per annum. At the end of 5 years, 15208.16. How much was invested? 1) 15208.16/1.04^5 2)12500}Exterior angles {Ans: They add up to 360. Divide by how many sides in the shape to find the angles.}Inverse proportion formula {Ans: x = 1/2y^2}Corresponding angles {Ans: Lie on the same side of the transversal and in corresponding positions. They are always equal}Plans and elevations {Ans: The plan is the top down view and the elevation is the side on view.}Algebraic fractions {Ans: "Express x/x+2 + 2x/x-4 as a single fraction in it's simplest form" 1) The opposite denominators go to the numerators of the first fraction. " x(x-4) + 2x (x+2) / (x+2)(x-4)" 2) From there, expand the brackets. "x^2 - 4x + 2x^2 + 4x/(x+2)(x+4)" 3) Simplify the numerator (DO NOT alter the denominator). " 3x^2/(x+2)(x+4)}