What are the first five terms of a geometric sequence in which the second term is 6 and the fourth term is 54

  2, 6, 18, 54, 162

Step-by-step explanation:

In a geometric sequence, terms that are 2 terms apart (2nd & 4th, for example) have a ratio that is the 2nd power of the common ratio. Since 54/6 = 9 = 3², the common ratio is 3.

The first term will be the 2nd term divided by that ratio; the 5th term will be the 4th term multiplied by that ratio. You can figure the 3rd term any of several ways (and they should all give the same value): multiply the 2nd term, divide the 3rd term, or find the geometric mean of the 2nd & 4th terms: √(6·54) = 18.

not only in mathematics, scientific proof also are required in the other field of science. also maths proofs are of particular structure, containing steps and logics. so proving is like doing science, it is science. that's why it is important to prove. 

an inaccurate proof leads to errors, or stating results that are not accurate.  which wil mess the probelm up you dont want this

just sum

10 + 10 = 20