In how many different orders can you line up 8 cards on a table

Which matrix multiplication is possible?

A, b, c, and d have the coordinates (-8, 1), (-2, 4), (-3, -1), and (-6, 5), respectively. which sentence about the points is true? a. a, b, c, and d lie on the same line. b. and are perpendicular lines. c. and are parallel lines. d. and are intersecting lines but are not perpendicular. e. and are parallel lines.

1mile equals approximately 1.6 kilometers. which best approximates the number of miles in 6 kilometers?