Solving for 4 in the last equation yields Using 2 in the third equation, we obtain 6-5(2) 3 Now 3=-1 and 4=2 are used to find 2 in the second equation 7-7(-1)+4(2) Finally, c1 is obtained using the first equation 20+1(-4)-2(-1)-3(2) 3. 4 The condition that akk #0 is essential because equation(2.6) involves division by akk. If this requirement is not fulfilled, either no solution exists or infinitely many solutions exist
Example 3. 13. Show that there is no solution to the linear system I 4x1-x2+2x3+34=20 0℃2+703-4x4=-7 63+54=-4 3 2 4