Hi. First time posting, and with a big A level exam coming up tommorow - I hope to make it a good first post

In every single paper so far, there seems to be a Quadratic Equation (I think a Quadratci inequality question?). Heres an example of one:

"The quadratic equation (k+1)x^2 + 12x + (k-4) = 0 has real roots.

(a) Show that k^2 - 3k -40 < 0... See more

(b)Hence find the possible values of K."

If someone could walk be through both questions it would be greatly appreciated. Could meant the difference between a grade or 2!