Calculate x to 3 places of decimal: \begin{array}{l} \text { i) }\\ 3^{x} 5^{x}=2 \end{array} \begin{array}{l} \text { ii) }\\ 7^{7 x} 4^{4 x}=2^{2 x+1} \end{array} \begin{array}{l} \text { iii)

}\\ 5^{x+2} 3^{2 x+1}=6^{x+2} \end{array} \text { iv) } \quad 2^{3 x+3} 7^{x+1}=3^{2 x+2}