Quandaries and Queries
Who is asking: Teacher
210 = -1/2x - 1
If you look to get to a common base I'm not sure how to deal with the negative in front of the one half.
The negative in front of the one-half is a problem.
If a is any positive real number and b is any real number then ab is positive. Hence the left side of the equation
is positive and the right side is negative. Thus there is no x that makes the equation valid so there is no solution.
Randy wrote back.
There should be a bracket around the -1/2 as it is the common ratio.
You are starting at 25 and succesively multiplying by -1/2 andyou want to know how many times you have to do this to get to 1/32 = 1/25.
so k=10 and the term you're after is the 11th term.