(5+a)² + 2(3a-1)

Expanding the square of (5+a):

(5+a)² = (5+a)(5+a) = 25 + 5a + 5a + a² = 25 + 10a + a²

Now substitute this back into the original expression:

(25 + 10a + a²) + 2(3a-1)

Expanding the second term:

2(3a-1) = 23a - 21 = 6a - 2

Now put it all together:

(25 + 10a + a²) + (6a - 2) = 25 + 10a + a² + 6a - 2

Combining like terms:

25 + 16a + a²

Therefore, the expression simplifies to:

a² + 16a + 25

You're welcome! If you have any more questions, feel free to ask))))))))