Final answer:
To find the value of z using Cramer's rule, calculate the determinants of the coefficients matrix and the matrix obtained by replacing the coefficients of z with the constants, and then divide the determinant of z by the determinant of the coefficients.
Step-by-step explanation:
To use Cramer's rule to find the value of z in the given system of equations:
- Identify the coefficients of x, y, and z, and the constants on the right side of each equation.
- Calculate the determinant of the coefficients matrix, denoted as D.
- Calculate the determinant of the matrix obtained by replacing the coefficients of z with the constants, denoted as Dz.
- Find the value of z by dividing Dz by D.
For the given system of equations:
x - 3y - z = -10
x - 5y - 5z = 8
-2x - 2y + 2z = -68
The determinant D evaluates to -10, Dz evaluates to -5, and the value of z is -5/-10, which simplifies to 0.5.