00:01
Given the system, 4x minus y plus z equals negative 5, 2x plus 2y plus 3 z equals 10, and 5x minus 2y plus 6 z equals 1, we want to solve using kramer's rule, which says that x is equal to d sub x over d, now y is equal to d sub y over d and z is equal to d sub z over d.
00:36
So let's first find the determinant of the coefficient matrix.
00:43
I'm going to use a calculator to speed this set, but we've got coefficients of 4, negative 1, 1, 2, 2, 3, and 5, negative 2, 6.
01:04
All right the determinant of that matrix is 55 now d sub x would be replacing the x column with the constants negative 5 10 1 in calculating the determinant which is negative 55 so x is equal to negative 1 then the d sub y is replacing the the y column with the constants, negative 5, 10, 1.
02:02
And that has a determinant of 165...