How do I expand a factorised expression?
Take example (x+3)(x-4) We use FOIL - first, outer, inner, last We multiply each part by the other part. First -> x times x = x2 . Outer -> x times -4 = -4x (remember the minus infront of the 4), Inner -> 3 times x = 3x. Last - -4 times 3 = -12 (again, remember minus infront of the 4) We then add the four answers from FOIL together: x2-4x+3x-12 From here we can simplify: x2-x-12
SK
Related Maths GCSE answers
All answers ▸Find the roots of the formula x^2 + 4x + 3 by factorising.
n is an integer greater than 1. Prove algebraically that n^2-2-(n-2)^2 is always an even number
ABC, DEF and PQRS are parallel lines. BEQ is a straight line. Angle ABE = 60° Angle QER = 80° Work out the size of the angle marked x. Give reasons for each stage of your working.
What is the gradient of the graph y = 3x^2 + 5x + 2, when x is 4?