Thursday, December 1, 2016

`5x - 3y + 2z = 3, 2x + 4y - z = 2, x + y - z = -1` Solve the system of linear equations and check any solutions algebraically.

Eq. 1 : `5x-3y+2z=3`


Eq. 2 : `2x+4y-z=2`


Eq. 3 : `x+y-z=-1`


Multiply Eq. 2 by 2 and add Eq. 1,


`4x+8y-2z=4`


`5x-3y+2z=3`


Eq.4 : `9x+5y=7`


Subtract Eq. 3 from Eq. 2,


Eq.5 : `x+3y=3`


Now let's solve Eq.4 and Eq.5 by substitution method,


From Eq.5 ,


`x=3-3y`


Substitute the above expression of x in the Eq.4,


`9(3-3y)+5y=7`


`27-27y+5y=7`


`27-22y=7`


`-22y=7-27`


`-22y=-20`


`y=(-20)/-22`


`y=10/11`


Plug in the value of y in the expression of x,


`x=3-3y`


`x=3-3(10/11)`


`x=3-30/11`


`x=(33-30)/11`


`x=3/11`


Plug in the values of x and y in the Eq.3,


`3/11+10/11-z=-1`


`13/11-z=-1`


`-z=-1-13/11`


`-z=(-11-13)/11`


`-z=(-24)/11`


`z=24/11`


Solutions of the equations are x=3/11 , y=10/11 and z=24/11

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