9514 1404 393
Answer:
(c) factoring and the zero-product principle
Step-by-step explanation:
Factoring is always an efficient method of solving a quadratic, if it has nice integer factors that can be easily identified. Here, the two prime factors of 35 have a sum of 12, so the factored form is easily found to be ...
(x +5)(x +7) = 0
This basically shows you the solutions are x=-5 and x=-7 "by inspection" in one step.
By contrast, the quadratic formula has 4 multiplications, a division, a square root, and 3 additions. That's a significant amount of arithmetic to get to the answers.
Factoring is the most efficient way to solve this quadratic.
