Read https://www.wyzant.com/resources/answers/2997/how_do_you_figure_out_how_to_determine_the_best_method... and I think that will answer your question (:
Answer:
4x-12 or 4(x-3)
Step-by-step explanation:
9x+9+2x-7(3+x)
9x+2x+9-21-7x
11x-12-7x
11x-7x-12
4x-12
Standard error (SE)

Or

Therefore, SE of the mean = (8)/(2) =4
Answer:
the measure of angle x is 48
Your answer is 62.5. Hope i helped