Question

Which of the following would best be solved using factoring by grouping?

3x^2 + 12x = 8 or x^2 + 3x - 10 = 0 or x^2 = 25 or x^3 + 5x^2 - 9x - 45 = 0

Answer 1

the last one: x^3 + 5x^2 - 9x - 45 = 0

Explanation:

You can solve all the other ones by simple factoring and/or calculator.

Since the last one has more than 3 terms, it's likely that you'll have to use group factoring to solve it.