How do you test for convergence of #Sigma (3n-7)/(10n+9)# from #n=[0,oo)#?
By putting an limit in front.
In this case, if the result is
But the result is something that we cannot solve.
So we are going to isolate n in the equation:
And we just have to solve it!
The result is
(I'not an english speaker so I don't know the name of this method. Feel free to add it.)