In this lesson, you will learn how to multiply matrices together. We have specific rules on the size of each matrix in order to multiply them. The number of columns of the first matrix must match the number of rows of the second matrix, otherwise they can't be multiplied. We multiply elements together and add the results and arrive at a third matrix which is the answer. Multiplying matrices has many uses. For example in physics, the dot product of two vectors can be thought of as two matrices multiplied together. In this case the first matrix would be a row vector and the second matrix would be written as a column vector. More Lessons: http://www.MathAndScience.com Twitter: https://twitter.com/JasonGibsonMath