Do you mean:
$$x^{\frac{1}{2}}x^4x=3*\frac{3}{4}$$
If so:
$$x^{\frac{11}{2}}=\frac{9}{4}$$
$$x=(\frac{9}{4})^{\frac{2}{11}}$$
$${\mathtt{x}} = {\left({\frac{{\mathtt{9}}}{{\mathtt{4}}}}\right)}^{\left({\frac{{\mathtt{2}}}{{\mathtt{11}}}}\right)} \Rightarrow {\mathtt{x}} = {\mathtt{1.158\: \!865\: \!903\: \!503\: \!021\: \!3}}$$
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Or did you mean:
$$x^\frac{1}{2}x^4x^{-3\times \frac{3}{4}}$$
which simplifies to:
$$x^{\frac{1}{2}+4-\frac{9}{4}}=x^{\frac{9}{4}}$$
Or did you mean something else entirely?
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