Is the language of words having same number of a's and b's context-free?
This language L = { w | w has equal number of as and bs and w≠ ε (since you put a +)  } is a CFL
A PDA would work as follows :
On reading a :
If the stack is empty or the top of the stack is a push a
If the top of stack is b pop b push nothing
On reading b :
If the stack is empty or the top of the stack is b push b
If the top of stack is a pop a push nothing
At the end of input if stack is empty accept else reject