We match the 1st members (1 and 7), multiply them, likewise for the 2nd members (2 and 9) and the 3rd members (3 and 11), and finally sum them up. Want to see another example? Here it …

For a 3×3 matrix multiply a by the determinant of the 2×2 matrix that is not in a 's row or column, likewise for b and c, but remember that b has a negative sign!

Example: a matrix with 3 rows and 5 columns can be added to another matrix of 3 rows and 5 columns. But it could not be added to a matrix with 3 rows and 4 columns (the columns don't …

Using Matrices makes life easier because we can use a computer program (such as the Matrix Calculator) to do all the "number crunching". But first we need to write the question in Matrix form.

In that example we were very careful to get the multiplications correct, because with matrices the order of multiplication matters. AB is almost never equal to BA.

Notice how we multiply a matrix by a vector and get the same result as when we multiply a scalar (just a number) by that vector. How do we find these eigen things?

Get in some serious multiplication training. Responds to your answers, so it trains your weaknesses.

Then use the Math Trainer - Multiplication to train your memory, it is specially designed to help you memorize the tables. Use it a few times a day for about 5 minutes each, and you will learn …

But we have to be careful what order we do the transforms in! It also shows us why the order of multiplying matrices is important (unlike ordinary numbers which can be mulitiplied in any …

The number of columns of the 1st matrix must equal the number of rows of the 2nd matrix. And the result will have the same number of rows as the 1st matrix, and the same number of …