I have the equation -2x^2+3x+7=0

So using the quadratic forumla I have

-3 plus or minus sqrt(3^2-4(-2)(7))/-4

= -3 plus or minus sqrt(65)/-4

Now, in the solutions manual it has the solutions as

(3 - sqrt(65))/4 , (3+sqrt(65))/4

Just wondering, but why did the denominator of the solutions become positive? and why did the the 3 also become positive? Thanks!!!

Thanks