Solve: $\frac{x}{2}+\frac{y}{3}=2$ and $x+y=5$. Find $x$.

**Steps**:
1. From one equation, express ONE variable in terms of the other.
2. Substitute into the OTHER equation. You get a one-variable equation.
3. Solve.
4. Plug back to find the other variable.

**Example**: $2x+3y=12$ ... (i); $x-y=1$ ... (ii).
- From (ii): $x=y+1$.
- Substitute in (i): $2(y+1)+3y=12$ → $5y+2=12$ → $y=2$.
- Then $x=2+1=3$.
- Solution: $(x,y)=(3,2)$.