Answer:
[tex]y=8x, \\y=12x[/tex]
Step-by-step explanation:
Proportional functions can be written as [tex]y=kx[/tex], where [tex]k[/tex] is some constant of proportional. Since directly proportional functions always pass through the origin, the y-intercept must be 0 (no additional number before or after [tex]x[/tex] term). The only answers that fit this format are:
[tex]\rightarrow \boxed{y=8x}\\\rightarrow \boxed{y=12x}[/tex]