OpenSAT

We can solve for $x$ using the substitution method. Solving the second equation for $y$, we get $y = x - 1$. Substituting this into the first equation gives us $2x + 3(x - 1) = 12$. Simplifying the equation, we get $2x + 3x - 3 = 12$, or $5x - 3 = 12$. Adding 3 to both sides gives us $5x = 15$. Dividing both sides by 5, we get $x = 3$.