Pls help me The formula for any geometric sequence is an = a1 · rn - 1 , where an represents the value of the n th term, a1 represents the value of the first term, r represents the common ratio, and n represents the term number. What is the formula for the sequence 2, -6, 18, -54, ...?

an = 2 · 3 n - 1
an = 2 · (-3) n - 1
an = -3 · 2 n - 1
an = 3 · 2 n - 1

Which has the greater energy, light of wavelength 519 nm or light with a frequency of 5.42 x 10^8 sec^-1?

What are the solutions of the equation x4 – 5x2 – 14 = 0? use factoring to solve. someone !

Georgia needs to buy flea treatment for her dog. pet store 1 is offering the flea treatment for 40 percent off plus an additional 25 percent off their regular price of $33. pet store 2 is offering the same flea treatment for 55 percent off plus an additional 5 percent off their regular price of $34. which location is offering the better price and how much cheaper is it? the flea treatment is $0.31 cheaper at pet store 2. the flea treatment is $1.05 cheaper at pet store 2. the flea treatment is $2.05 cheaper at pet store 1. the flea treatment is $2.36 cheaper at pet store 1.