Verified answer

Break even profit is given by:

TR = TC

60* Q = 10*Q + 100

Solve for Q:

50*Q = 100

Q = 2. Revenue = costs when Q = 2. Check. TR = 120. TC = 10*2 + 100 = 120.

You are going about this difficulty the wrong method. First set the equation equal to zero. 0= -X^2+2x+4 (observe the neg. Symbol in front of the X^2. This equation can't be factored or "allotted into paretheses" as you call it so that you have to use the quadratic components. The quadratic system contains 3 variables... A, B, and C. For this equation you've got A= -1, B=2, C=4. Plug in and clear up for X. X= 1+2√5 /-2 simplify and you have your reply! Obviously no matter what you do you're going to now not get a √6 so C is out... And if A is right then what occurred to the two before the √5? So A is wrong additionally... That leaves you with... B. Final answer.