Question

4x-y+3z=-10 ...(1)
3x+y+2z=-16 ...(2)
2x+4y+3z=-29 ...(3)
Jika penyelesaian sistem persamaan tersebut (p,q, r ) nilai p-q-r=...

Answer 1

4x-y+3z=-10

-    +   -  = -

2x+4y+3z=-29

____________

2x+3y=19___4

_________

Eq.1 multiplied by2 & eq.2 is multiplied by 3

8x-2y+6z=-20

-    +    -   = -

9x+3y+6z=-48

___________

-x+y=28___5

_________

Eq.5 multiplied by 2

-2x+2y=56------(5)

2x+3y=19-------(4)

_________

    5y=75

      Y= 15

Substitute y value in Eq.5

 -x+15=28

    -x=28-15

     X=-13

Subs.X & Y value in Eq.1

(4*-13)-15+3z=-10

 -52-15+3z=-10

             3z=-10+67

              3z=57

               Z=19

Conformation

Subs x y z value in any eq.

P-q-r=-13-15-19=-47

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