$$ \begin{aligned} 30+5(x-3) &= 2x+2(x+4)&& \text{simplify left and right hand side} \\[1 em]30+5x-15 &= 2x+2x+8&& \\[1 em]5x+15 &= 4x+8&& \text{move the $ \color{blue}{ 4x } $ to the left side and $ \color{blue}{ 15 }$ to the right} \\[1 em]5x-4x &= 8-15&& \text{simplify left and right hand side} \\[1 em]x &= -7&& \\[1 em]x &= -7&& \\[1 em] \end{aligned} $$

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