Find the solutions of the equation x^2 - 2x - 8 =0

First factorise the equation into 2 sets of brackets: You can do this by looking at the constant in the quadratic, 8. Try and find 2 numbers that multiply together to make 8 (such as 4 and 2), and that can be added or subtracted to make the coefficient of the middle term, 2. This results in: (x-4)(x+2)=0. To make the equation true, the left side must equal 0. Either bracket can equal 0. For the first let x=4 (as 4-4=0). For the second, x=-2. These are the answers, x=4 and x=-2