解方程(1) a+2b+3=0 b+3c=1 a-c=2

来源:百度知道 编辑:UC知道 时间:2024/05/15 03:22:36
有步骤

a+2b=-3...........①
b+3c=1.............②
a-c=2..............③
解:
①-③,得
2b+c=-5
上式与②联立,得
2b+c=-5··········④
b+3c=1···········⑤
④-⑤×2,得
-5c=-7
c=7/5
将c=7/5代入⑤,得:b=-16/5,
将c=7/5代入③,得:a=17/5;
综上,得
a=17/5
b=-16/5
c=7/5

c=a-2

b+3a-6=1
a+2b+3=0

a=0-2b-3
b+(0-2b-3)*3-6=1
b+0-6b-9=7
-5b=16
b=-3.2

a=3.2*3-3
a=3.4

c=1.4

a+2b+3=0......(1)
b+3c=1.......(2)
a-c=2......(3)
(1)-(2)x2 :a-6c=-5....(4)
(3)-(4) :5c=7 c=7/5
代入(3):a=17/5
代入(2):b=-16/5