Respuesta :

Answer:

y=2

Step-by-step explanation:

3x+4y=20

3*4+4y=20

12+4y=20

4y=20-12

4y=8

y=8/4

y=2

Step-by-step explanation:

The answer is 2, 3*4= 12 and 4*2=8. if you add both of them you get 20.