$$ \begin{aligned} 4x-7 &= x+4\cdot(4+x)&& \text{simplify right side} \\[1 em]4x-7 &= x+16+4x&& \\[1 em]4x-7 &= 5x+16&& \text{move the $ \color{blue}{ 5x } $ to the left side and $ \color{blue}{ -7 }$ to the right} \\[1 em]4x-5x &= 16+7&& \text{simplify left and right hand side} \\[1 em]-x &= 23&& \text{switch signs on both sides} \\[1 em]x &= -23&& \\[1 em] \end{aligned} $$

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