Which of the following is the image of d after a rotation of 90° about the origin?

(-2, 1)
(2, 1)
(-1, -2)

I've never been good at math he told he loves but he keeps cheating on me, so it ain't adding up sis

Which expression is equivalent to (3^2)^-2 a.-81 b.-12 c.1/81 d.1/12

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