#### Answer

{(x,y)|y=3x-4}
infinitely many solutions

#### Work Step by Step

y=3x-4
Plug this value for y into the other equation.
9x-3y=12
9x-3(3x-4)=12
9x-3(3x)-3(-4)=12
9x-9x+12=12
12=12
Since this statement is true, there are infinitely many solutions and the solution set contains either of the equations from the system. For example, {(x,y)|y=3x-4}.