{x+y+z=1 {x+3y+7z=2 {x+5y+19z=4

问题描述:

{x+y+z=1 {x+3y+7z=2 {x+5y+19z=4

(2)-(1):2y+6z=1(4)
(3)-(1):4y+18z=3(5)
(4)×2:4y+12z=2(6)
(5)-(6):6z=1 z=1/6
(4)×3:6y+18z=3(7)
(7)-(5):2y=0y=o
将y=0,z=1/6带入(1) 得x=5/6