sequences

[nigga7]

in a geomatric progressionthe second term is 9 less than the first term.the sum of the second and thirdterm os 30,given that all termsi the progression are positive,find the first term..... NEED HELP HERE GUYS

 

[blueberryyums]

You need to use simultaneous equation. Equate what you just type out in maths terms.

 

[nigga7]

You need to use simultaneous equation. Equate what you just type out in maths terms.

can u write the solution here?

 

[HubbaBubba]

1st term = a
2nd term = a-9
third term = ar^2

Sum = a-9 + ar^2 = 30
When you make r the subject of the equation you get (r^2 = 39/a - 1)
Then you substitute r in the sum equation, and you get a