Yep, got the solution but just in case this is one of your school problems I'd best not give you the answer. All I will say is complex numbers, nice.

I literally made it up on the spot while typing it out into the signature box I better had complete it now, so I know if other's get it right!

Isn't it actually x = -1 +/- i? Liam, I assume you're doing quadratic equations at school? Set the two expressions you've been given as being equal (as you're told in the question) and then get it into the form 0 = ax^2 + bx + c The use the quadratic formula to get the value of x.

Erm no...I actually meant because the quadratic formula is (-b +/- sqrt(b^2-4ac))/2a. You only did the + part of that.

Yes of course! Though (-i)^2 and i^2 both equal sqrt -1, you are correct that it is from the quadratic equation that you get both of the answers for x. *EDIT* Actually were both correct. You just did it using the quadratic formula to calculate the answer. I did it from the quadratic equation and resolving as far as x=-1 + sqrt(-1) I just forgot that sqrt(-1) has two answers, -i and +i. What the quadratic formula reminds us of is that there are two answers to any sqrt, the positive and the negative hence ± in the formula.

Well done all I did this on paper last night... I forgot to change the minus to a plus on the 10 when transferring it over Solution: 5x^2+12x = 2(x-5) 5x^2+12x = 2x-10 5x^2+12x-2x+10=0 5x^2+10x+10=0 x=-b±sqrt(b^2-4ac)/2a x=-10±sqrt(10^2-4x5x10)/2x5 x=-10±sqrt(100-200)/10 x=-10±sqrt(-100)/10 x=-10+sqrt(-100)/10 OR x=-10-sqrt(-100)/10 x=-10+10i/10 or x=-10-10i/10 x=-1+i or x=-1-i

While I liked math, can't say I miss this stuff. I can say I have never had to do a quadratic equation in the 10 years I spent as a project engineer, then director of engineering. (Or 5 years since.)