Solve x2 + 2x − 4 = 0 leave in simplest form.
This is a Quadratic equation so you would try to factorise.If it was on the calculator paper use the equation (You don't need to memories this equation, but you have to be commutable using it).However this is not for a calculator paper so the first thing you should try is to find two numbers that multiply together to form -4 and add together to form 2. (But it is not possible and a hint is leave in simplest form the more you do the quicker to recognise if a equation can be factories).So go back to the Quadratic equation. for this question a:1 b:2 c:-4x=-2±√22-(4x1x-4) /2x1 x=-2±√4+16 /2 (+16 not -16 as - and - make a plus)√20= √4√5 = 2√5x=-2±2√ 5/2 Simplify and split the fraction in two so 2/2= 1±2√5 /2 = ±√5Therefore we have two answers 1+√5 & 1-√5
