Respuesta :

Answer:

5

Step-by-step explanation:

y = 15 - 3x

0 = 15 - 3x

15 - 0 = 3x

x = 5

Answer:

x=5

Step-by-step explanation:

y= 15-3x

We are to let y=0

0 = 15-3x

Add 3x to each side

3x= 15-3x+3x

3x=15

Divide by 3

3x/3 =15/3

x = 5