SOLUTION: Obtain an equivalent system by performing the stated elementary operation on the system. Replace the first equation by the sum of itself and 3 times the second equation. -7x -1

Algebra ->  Finance -> SOLUTION: Obtain an equivalent system by performing the stated elementary operation on the system. Replace the first equation by the sum of itself and 3 times the second equation. -7x -1      Log On


   

Question 1117714: Obtain an equivalent system by performing the stated elementary operation on the system. Replace the first equation by the sum of itself and 3 times the second
equation.
-7x -10y -14z= -35
6x -9y +3z= -24
5x +7y +8z= -20
Found 2 solutions by josgarithmetic, solver91311:
Answer by josgarithmetic(39630) About Me  (Show Source):
You can put this solution on YOUR website!
What to do was clearly stated for you, so that is what you need to do!

"Replace the first equation by the sum of itself and 3 times the second
equation. "

Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!



 -7x   -10y  -14z  =  -35
  6x   - 9y  + 3z  =  -24
  5x   + 7y  + 8z  =  -20

      3R2  =  18x  -27y  + 9z  = - 72
       R1  = - 7x  -10y  -14z  = - 35 
             ------------------------
 3R2 + R1  =  11x  -37y  - 5z  = -107 

  11x   -37y  - 5z  = -107
   6x   - 9y  + 3z  =  -24
   5x   + 7y  + 8z  =  -20

John

My calculator said it, I believe it, that settles it