The expression in the image is:

$(2x + 3)(x + 3x)$

Let's simplify and solve this expression:

1. First, simplify the expression inside the second parentheses: $x + 3x$. $x + 3x = 4x$ So, the expression now becomes: $(2x + 3)(4x)$

2. Now, distribute $4x$ across the terms in $2x + 3$: $(2x + 3)(4x) = 2x \cdot 4x + 3 \cdot 4x$

3. Calculate each term: $2x \cdot 4x = 8x^2$ $3 \cdot 4x = 12x$

4. Combine the results: $8x^2 + 12x$

So, the simplified expression is:

$8x^2 + 12x$

Would you like more details or have any questions?

Here are some related questions you might consider:

1. How would you solve $8x^2 + 12x = 0$?
2. What happens if you factor out the common terms in the expression $8x^2 + 12x$?
3. How would this change if the original expression had a different constant term in either factor?
4. What would the graph of $y = 8x^2 + 12x$ look like?
5. How can you use the quadratic formula to solve $8x^2 + 12x = c$ for some constant $c$?

Tip: Always check for like terms when simplifying expressions, as they can often be combined to simplify your calculations.