Let's simplify the given expression step by step:

$2a^2 - 7a + 5 + 6a^2 - 1$

1. Combine the like terms:
   • $2a^2$ and $6a^2$
   • $-7a$ (no other like terms)
   • $5$ and $-1$

$(2a^2 + 6a^2) - 7a + (5 - 1)$

2. Simplify:
   • $2a^2 + 6a^2 = 8a^2$
   • $5 - 1 = 4$

So, the simplified expression is:

$8a^2 - 7a + 4$

Would you like more details or have any other questions?

Here are 5 related questions to deepen your understanding:

1. How do you combine like terms in a polynomial?
2. What is the degree of the polynomial $8a^2 - 7a + 4$?
3. How do you factor the expression $8a^2 - 7a + 4$?
4. Can this expression be simplified further or solved for specific values of $a$?
5. How do you graph the quadratic function $8a^2 - 7a + 4$?

Tip: Always group and combine like terms first when simplifying expressions, as it helps in reducing complexity.