You can put this solution on YOUR website! x+2y-5z= -12
2x+2y-3z= -2
3x-4y-z=11
Determinant of
1===2====-5
2===2====-3
3==-4====-1
Determinant is 42 (calculator is far easier here)
solve for Dx by making a new matrix with the numerical constants in the x column. Find the determinant and then divide by the determinant just calculated.
-12===2===-5
-2====2===-3
11====-4===-1
Dx=168. Divide by determinant, and 168/42=4
solve for Dy, making a new matrix putting the numerical constants in the y column.
1====-12====-5
2====-2====-3
3====11====-1
Dy=-21 so dividing by determinant, y=-1/2. Do the same for the z column.
1====2===-12
2====2====-2
3===-4====11
Dz=126, and z=3
(4,-1/2,3)
Check
4-1-15=-12
8-1-9=-2
12+2-3=11
All check.
