00:01
So in order to solve this problem, we are going to put it into matrix form.
00:07
So our systems of equations can be changed in a matrix form by creating an a matrix, which is going to have all of our coefficients.
00:15
So it'll have 25, 61, negative 12 in the first row, and then 18, negative 12, 7 in the second, and 3, 4, and negative 1 in the 3rd.
00:28
This is going to be times our x matrix, which just has our variables, so it'll look exactly like this.
00:33
X, y, z, and then we create a b matrix on the right -hand side, which just is one column 15, negative 3, 12.
00:50
Now to solve for x, we multiply both sides times a inverse.
00:56
A inverse times a gives us the identity matrix, and the identity matrix times x is just x...