Which of the answer choices has matrix multiplication defined? please help!

State if the two triangles are congruent. if they are, state how you know?

The median of a data set is the measure of center that is found by adding the data values and dividing the total by the number of data values that is the value that occurs with the greatest frequency that is the value midway between the maximum and minimum values in the original data set that is the middle value when the original data values are arranged in order of increasing (or decreasing) magnitude

Ineed to know the answer to this algebra question.