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Please help Thank you

 

\(k, a_2, a_3\) and \(k, b_2, b_3\) are both nonconstant geometric sequences with different common ratios. We have \(a_3-b_3=3(a_2-b_2).\) 

Find the sum of the common ratios of the two sequences.

 Dec 21, 2020
 #1
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The sum of the common ratios is 3^2 + 3 = 12.

 Dec 22, 2020
 #2
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Use k in all your answers

 

What is the common ratio of the first one  ?

What is the common ratio of the second one  ?

 

You want a single number for the sum of these.

 

What is an expression for a_3?

What is an expression for b_3?

 

Now what?

 

Answer these then see if you can continue.   [ It will be useful to remember that x^2-y^2 = (x-y)(x+y)  ]

 Dec 22, 2020

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