$$ \begin{aligned} 5\cdot(9-2(6d-1)) &= 11\cdot(4-10d)-139&& \text{simplify left and right hand side} \\[1 em]5\cdot(9-(12d-2)) &= 44-110d-139&& \\[1 em]5(9-12d+2) &= -110d-95&& \\[1 em]5(-12d+11) &= -110d-95&& \\[1 em]-60d+55 &= -110d-95&& \text{move the $ \color{blue}{ -110d } $ to the left side and $ \color{blue}{ 55 }$ to the right} \\[1 em]-60d+110d &= -95-55&& \text{simplify left and right hand side} \\[1 em]50d &= -150&& \text{ divide both sides by $ 50 $ } \\[1 em]d &= -\frac{150}{50}&& \\[1 em]d &= -3&& \\[1 em] \end{aligned} $$

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