This paper is devoted to the study of biharmonic problems. More precisely, we consider the following inhomogeneous problem \begin{equation*} \begin{cases} {\Delta}^{2}u-µeft(\frac{u}{|x|^{4}}\right)=eft(\frac{|u|^{2^{*}(s)-2}u}{|x|^{s}}\right)+ambda eft(\frac{u}{|x|^{4-lpha}}\right)+f(x), & xı mega, u=\frac{ tial u}{ tial n}=0, & xı tialmega, \end{cases} \end{equation*} where $\Omega$ is a bounded domain in $\mathbb{R}^{N}$ and $N\geq 5$, under sufficient conditions on the data and the considered parameters, we prove the existence and multiplicity of solutions, by virtue of Ekeland's Variational Principle and the Mountain Pass Lemma.