x+x+5+2x+1

a+2a+10-3a

2x+5+2x+1

4x+5+1
4x+6 or 6+4x

I'm pretty sure that's right.

For the second problem, combine like terms. The a's cancel each other out (3a - 3a = 0) leaving you with 10.

Jill is right.

To simplify the expression x + x + 5 + 2x + 1, we can combine like terms, which means combining the terms with the same variable.

First, let's group the terms with the same variable:
x + x + 2x = 4x

Now, let's combine the constants:
5 + 1 = 6

Putting it all together, the simplified expression is:
4x + 6