#1**0 **

The common difference is -x/2. Therefore we have the sequence continue as:

2x, 3x/2, x, x/2, 0, -x/2, -x, -3x/2, -2x, -5x/2......etc.

And -5x/2 being the 10th term.

Guest Jun 26, 2017

#2**0 **

We have:

-5x/2 = 2x + (N - 1)* -x/2

Solve for N:

-(5 x)/2 = 2 x - 1/2 x (N - 1)

-(5 x)/2 = 2 x - 1/2 (N - 1) x is equivalent to 2 x - 1/2 (N - 1) x = -(5 x)/2:

2 x - 1/2 x (N - 1) = -(5 x)/2

Expand out terms of the left hand side:

(5 x)/2 - (N x)/2 = -(5 x)/2

Subtract (5 x)/2 from both sides:

-(N x)/2 = -5 x

Divide both sides by -x/2:

**Answer: | N = 10 which is the 10th term of your sequence.**

Guest Jun 26, 2017