Which equation involves a prime quadratic and cannot be solved by factoring? A. x2 + 6x + 9 = 0 B. x2 − x − 6 = 0 C. x2 + 3x − 4 = 0 D. x2 + 5x − 4 = 0
The answer is D, because the others can be solved. A when factored is equal to -3, when B is factored it is equal to 3,-1, when C is factored it is 1,-4. D can be solved but you will only get irrational numbers which can't be used.
