The complex number z and its complex conjugate Z satisfy the equation

$\displaystyle 2z + Z = \frac{11 + 7i}{1 + i}$

Find z in the form x + iy. [6]

This is a new topic I am doing in maths and I would like to know how this is done because I don't know the basics in answering it. I would greatly appreciate any help if you could tell me what methods are used. Thanks

note: "Z" actually symbolizes a little z with the line on top of it - z's conjugate, to clarify.