if , then we can write the equation in the form of you're done. but if you want the form , just factor the numerator by completing the square.

If E = 0, then you have the quadratic equation

note that if you use the quadratic formula in solving x, is the determinant, and if it is zero, you will be left with constant

same with b). but here, note that for a quadratic equation in one variable, if thediscriminantis positive, then you have two solutions for the variable, hence, you have two vertical lines.

same reasong with c) but this time, if the discrimiant is negative, the graph does not intersect the x axis (in 2-d), hence "no" points. (i have to include the quotation marks..)