1. The problem is to simplify the expression $3x + 2x$ using algebra tiles. 2. Algebra tiles represent variables and constants visually: a long rectangle for $x$ and small squares for units. 3. The expression $3x + 2x$ means you have 3 tiles representing $x$ plus 2 more tiles representing $x$. 4. When combining like terms, you add the coefficients of $x$: $3 + 2 = 5$. 5. So, $3x + 2x = 5x$. 6. Using algebra tiles, you would group all 5 $x$ tiles together to represent $5x$. 7. This shows that adding $3x$ and $2x$ results in $5x$. Final answer: $5x$