Answer:
£[tex]\frac{x - t - 200}{2}[/tex]
Step-by-step explanation:
His wage is £x.
He pays tax of £t.
He's left with £(x - t).
He then pays rent of £220.
He's now left with £(x - t - 220)
He shares what's left between himself and his wife. We are not told how exactly they shared it but we can assumed he shared it in half.
Therefore, each of them will get half of £(x - t - 220):
£[tex]\frac{x - t - 200}{2}[/tex]