Write the system of equation as a matrix equation of the form AX=B

X1-2x2+6x3=-5
-2x1+3x2
x1+x2=7x3=-6

To write the system of equations as a matrix equation of the form AX = B, we need to arrange the coefficients of the variables in matrix A, the variables in matrix X, and the constants on the right-hand side in matrix B.

The given system of equations is:
X1 - 2X2 + 6X3 = -5
-2X1 + 3X2 = ?
X1 + X2 + 7X3 = -6

From the second equation, we can see that the coefficient of X3 is missing. So, let's assume it is 0 for now.

The system of equations can be written as:

| 1 -2 6 | | X1 | | -5 |
| -2 3 0 | | X2 | = | ? |
| 1 1 7 | | X3 | | -6 |

This is the matrix equation of the form AX = B, where A is the coefficient matrix, X is the variable matrix, and B is the constant matrix.