$$ \begin{aligned} 10+\frac{18}{9}x\cdot(7-4) &= 0&& \text{multiply ALL terms by } \color{blue}{ 9 }. \\[1 em]9\cdot10+9 \cdot \frac{18}{9}x\cdot(7-4) &= 9\cdot0&& \text{cancel out the denominators} \\[1 em]90+54x &= 0&& \text{ move the constants to the right } \\[1 em]54x &= -90&& \text{ divide both sides by $ 54 $ } \\[1 em]x &= -\frac{90}{54}&& \\[1 em]x &= -\frac{5}{3}&& \\[1 em] \end{aligned} $$

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