For each ordered pair, determine whether it is a sol
$$\{\begin{array}{l}12x+3y=9\\ y=-4x+3\end{array}$$
$$\text{Unknown environment 'tabular'}$$

Step 1 ：Substitute x = 0 and y = -7 into the first equation: $12(0)+3(-7)=9$

Step 2 ：$0-21=9$

Step 3 ：$-21\ne 9$

Step 4 ：Therefore, (0,-7) is not a solution to the system of equations.

Step 5 ：Substitute x = 3 and y = -9 into the first equation: $12(3)+3(-9)=9$

Step 6 ：$36-27=9$

Step 7 ：$9=9$

Step 8 ：Then substitute x = 3 and y = -9 into the second equation: $-9=-4(3)+3$

Step 9 ：$-9=-12+3$

Step 10 ：$-9=-9$

Step 11 ：Therefore, (3,-9) is a solution to the system of equations.

Step 12 ：Substitute x = -2 and y = 11 into the first equation: $12(-2)+3(11)=9$

Step 13 ：$-24+33=9$

Step 14 ：$9=9$

Step 15 ：Then substitute x = -2 and y = 11 into the second equation: $11=-4(-2)+3$

Step 16 ：$11=8+3$

Step 17 ：$11=11$

Step 18 ：Therefore, (-2,11) is a solution to the system of equations.

Step 19 ：Substitute x = 1 and y = 5 into the first equation: $12(1)+3(5)=9$

Step 20 ：$12+15=9$

Step 21 ：$27\ne 9$

Step 22 ：Therefore, (1,5) is not a solution to the system of equations.

Step 23 ：So, the solutions to the system of equations are $\boxed{{\displaystyle (3,-9)}}$ and $\boxed{{\displaystyle (-2,11)}}$.