用列主元消元法解方程组—X1+2X2=2；—X1+3X3=1；2X1-X2-X3=1

Question

用列主元消元法解方程组 —X1+2X2=2；—X1+3X3=1；2X1-X2-X3=1

Answer 1

一2X1-X2-X3=1 二2X1-X2-X3=1 三 2X1-X2-X3=1
-X1+3X3=1 -0.5X2+2.5X3=1.5 1.5X2-0.5X3=2.5
-X1+2X2=2 1.5X2-0.5X3=2.5 2.3X3=2.3
用回代过程解方程组三得 X1=2 X2=2 X3=1