John and Nadim do the math homework together. When they find 9 - (-8), they get different answers. John claims the difference is 17. Nadim claims the difference is -1. Who is correct?

Identify a1 and r for the geometric sequence an= -256(-1/4) n-1

which of the following sets of data would produce the largest value for an independent-measures t statistic? the two sample means are 10 and 20 with variances of 20 and 25 the two sample means are 10 and 20 with variances of 120 and 125 the two sample means are 10 and 12 with sample variances of 20 and 25 the two sample means are 10 and 12 with variances of 120 and 125

Ithink i know it but i want to be sure so can you me out ?