Can someone explain how the following Matrix can be multiplied? I thought the column of the first matrix had to match the row of the second and the row of the first had to match the column of the second. I how the matrices listed below as (1x3) and (3x3) respectively. Yet my online Pre-cal course says it's possible. Please explain why this is so.

What is the slope of the line that contains the points (-2,1) and (0,-3)

What is the absolute value of -100000000000000?

If your score on your next statistics test is converted to a z score, which of these z scores would you prefer: minus2.00, minus1.00, 0, 1.00, 2.00? why? a. the z score of 2.00 is most preferable because it is 2.00 standard deviations above the mean and would correspond to the highest of the five different possible test scores. b. the z score of 0 is most preferable because it corresponds to a test score equal to the mean. c. the z score of minus2.00 is most preferable because it is 2.00 standard deviations below the mean and would correspond to the highest of the five different possible test scores. d. the z score of minus1.00 is most preferable because it is 1.00 standard deviation below the mean and would correspond to an above average