How do you simplify the expression x² + 15x + 56x + 7?

To simplify the expression x² + 15x + 56x + 7, we can follow these steps:

1. Combine like terms: In this expression, we have two like terms related to ‘x.’ These are 15x and 56x.
2. Adding these together gives us:
3. 15x + 56x = 71x

Now we can rewrite the expression:

x² + 71x + 7

So, the simplified form of the expression x² + 15x + 56x + 7 is x² + 71x + 7.