hi another question

Question

hi, thank you for the help on the other one..i understand now... 

so i now have :

2y+3z=18

6y+4z=44

 

thank you!

Answer 1

2Y +3Z = 18

 6Y +4z = 44

 

 

Multiply first equation by - 3 , and add the 2 equations:

 

 -3 ( 2Y + 3Z = 18)

       6Y  + 4Z = 44    

      0Y  - 5Z = -10

 

         Z = -10/ -5 = 2

 

   Substitute in the first equation:

  

 

     2Y + 3 ( 2 ) = 18

 

    2Y = 18 -6 = 12

 

       Y =6

 

    Test :

 

      2( 6 ) + 3 (2) = 18

 

      6 ( 6) + 4 ( 2 ) = 44

     

    Checks

 

Answer 2

The easiest thing would be to eliminate the y terms again.  Multiply the first equation by -3 and add it to the second equation:

 

(-3)(2y+3z) = (-3)(18)

-6y -9z = -54

 

 -6y -9z = -54

+6y+4z =  44

-----------------

   0 + -5z = 10

 

Can you finish it from here?