Solve x^2+2x-8=0

x=-4, x=2When you see a quadratic equation like this, the first thing you should try and do is factorise it. You need to find two numbers that add together to make the second term of the equation - in this case, 2x - and multiply together to make the third term of the equation - in this case, -8. -8 has 4 sets of factors - (8, -1), (-8, 1), (-4, 2) and (-2, 4). Now we need to see which of these add together to make 2.8+-1=7, so the first pair doesn't work. -8+1=7, so the second pair doesn't work. -4+2=-2, so the third pair doesn't work. -2+4=2, so it must be this pair. Therefore, we can factorise the equation as follows:x^2+2x-8=0 -> (x+4)(x-2)=0To make this equation true, either x+4=0 or x-2=0, so x=-4 or x=2.