I agree. I was staring at their addition of the two infinite series for a while trying to make sense of it. It doesn't make sense. It also doesn't address the fact that using the formula for an infinite geometric series (S = a / (1 - r)) with a = 1 and r = -1 doesn't work here.

## I agree. I was staring at

I agree. I was staring at their addition of the two infinite series for a while trying to make sense of it. It doesn't make sense. It also doesn't address the fact that using the formula for an infinite geometric series (S = a / (1 - r)) with a = 1 and r = -1 doesn't work here.

Not impressed.