Matrix multiplication (2X2) and (2X4) with negative numbers

This video demonstrates how matrix multiplication should be done when the order of the first matrix is 2x2 and the order of the second matrix is 2x4 and some of the elements of the matrices are negative numbers.

[Professorjake]

this is amazing! thank you. makes this type of thing sure easy!

[lechiffrebeats]

this could have been shown in a 5 seconds clip with a few arrows