x+x+5+2x+1

Answer 1

a+2a+10-3a

Answer 2

2x+5+2x+1
4x+5+1
4x+6 or 6+4x

I'm pretty sure that's right.

Answer 3

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

Jill is right.