SOLUTION: what is the first number of a geometric sequence if the next two numbers are 3 and 17

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Question 965511: what is the first number of a geometric sequence if the next two numbers are 3 and 17
Answer by Edwin McCravy(20056) About Me  (Show Source):
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what is the first number of a geometric sequence if the next two numbers are 3 and 17

Let the first term be x:

The sequence goes

x, 3, 17

2nd term ÷ 1st term = 3rd term ÷ 2nd term
    3    ÷     x    =    17    ÷    3
          
Get the equation all together:

                3÷x = 17÷3
                3%2Fx+=+17%2F3

Cross multiply:

                  9 = 17x

Divide through by 17

               9%2F17 = x
                  

The sequence is 9%2F17, 3, 17  

Answer: 9%2F17
             
Edwin