An m times n upper triangular matrix is one whose entries below the main diagonal are zeros, as is shown in the matrix to the right. when is a square upper triangular matrix invertible? justify your answer.

A square matrix is invertible when its determinant is non-zero. An upper-triangular square matrix will have a non-zero determinant if there are no zeros on the diagonal.

The determinant is the sum of the values in a row or column multiplied by the determinant of the corresponding cofactor matrix. When all matrix entries below the diagonal are zero, the determinant becomes the product of diagonal terms.

x=4

step-by-step explanation:

given the equation is 8+9z=-6, the first step would be to subtract the 8 from both sides:

8+9z-8=-6-8

since 8 minus 8 = 0, this would cancel out the 8. and since -6 minus 8 equals -14, the equation would look like this

9z = -14