You can use substitution to solve this.
Let's look at the 2nd equation. 2x+3y=29.
In the first equation, we know that x=12-y. So, substitute that in for the 2nd equation. Do that and we have 2(12-y)+3y=29.
Distribute the 2.
24-2y+3y=29.
Combine like terms.
24+1y=29
Subtract the 24, then subtract on the other side of the equation too.
24-24=0, 29-24=5
So now we know that y=5.
Substitute this for the first equation now to find x.
x=12-5
x=7
Final answer: (7,5) or x=7 y=5
