Respuesta :

1. Rewrite the system:

 x+12y=68  (i)
 x=8y-12   (ii)

 2. Let's substitute the equation (ii) into the equation (i):

 x+12y=68
 (8y-12)+12y=68

 3. Then, you have:

 8y-12+12y=68

 4. When you clear "y", you have:

 20y-12=68
 20y=68+12
 20y=80
 y=80/20
 y=4

 5. You already have the value of "y". Now, you must substitute this value into the equation (ii):

 x=8y-12
 x=8(4)-12
 x=32-12
 x=20

 6. Therefore, the result is:

 x=20
 y=4