Here are solutions for the section 9 of the 2013-14 SAT practice test; you can find the test at the College Board's web site or in the Getting Ready for the SAT booklet. The following solutions illustrate faster, less formal methods that may work better than formal methods on a fast-paced test such as the SAT. To learn more about these methods, see my e-book Succeeding in SAT Math or the SAT math tips page.
However, if you miss the above insight, you could solve for x, find that x = −2 or x = 3, eliminate choices (A), (B), and (C), and then substitute −2 and 3 in (D) and (E) to see which is true.