use elimination to solve each system of equations 例子:X- Y= 1 X + Y= 3 and 3x-y=26 -2x-y= -24

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use elimination to solve each system of equations 例子:X- Y= 1 X + Y= 3 and 3x-y=26 -2x-y= -24

use elimination to solve each system of equations 例子:X- Y= 1 X + Y= 3 and 3x-y=26 -2x-y= -24
use elimination to solve each system of equations
例子:X- Y= 1 X + Y= 3 and 3x-y=26 -2x-y= -24

use elimination to solve each system of equations 例子:X- Y= 1 X + Y= 3 and 3x-y=26 -2x-y= -24
利用消元法求解每个方程组
1.x-y=1 (1)
x+y=3 (2)
解 (2)-1×(1)代替(2),原方程组化为
x-y=1 (1)
2y=2 (2)
解得y=1代入(1)得x-1=1,x=2,故方程组的解为
x=2,y=1.
2.3x-y=26 (1)
-2x-y=-24 (2)
解 (2)-(-2/3)×(1)代替(2),原方程组化为
3x-y=26 (1)
(-5/3)y=-20/3 (2)
解得y=4代入(1)得3x-4=26,x=10,故方程组的解为
x=10,y=4.

in Chinese

不是消除法,中文好像叫做加减消元法!

例子:X- Y= 1
X + Y= 3
x=2,y=1
3x-y=26
-2x-y= -24
x=10,y=4

加减消元法
1、X- Y= 1 (1)
X + Y= 3 (2)
(1)+(2)得 2x=4 x=2
把x=2代入(1)得 y=1
即 x=2 y=1
2、3x-y=26 (1)
-2x-y= -24 (2)
(1)-(2)得 5x=50 x=10
把x=10代入方程(1)得 3×10-y=26 x=10
即 x=10 x=10