Simple Trick!

Algebra Level 4

Let $$a$$ be a real number and let $$(4a+3)^4+(4a-1)^4=322$$. If the positive solution for $$a$$ can be expressed as $$\dfrac{n\sqrt{k}-x}{y}$$, with $$n$$, $$k$$, $$x$$ and $$y$$ all co-prime positive integers, find $$(n+k)^{y-x}$$

×