$$ \begin{aligned} 6+\frac{12}{x+3} &= 0&& \text{multiply ALL terms by } \color{blue}{ x+3 }. \\[1 em](x+3)\cdot6+(x+3)\cdot\frac{12}{x+3} &= (x+3)\cdot0&& \text{cancel out the denominators} \\[1 em]6x+18+12 &= 0&& \text{simplify left side} \\[1 em]6x+30 &= 0&& \text{ move the constants to the right } \\[1 em]6x &= -30&& \text{ divide both sides by $ 6 $ } \\[1 em]x &= -\frac{30}{6}&& \\[1 em]x &= -5&& \\[1 em] \end{aligned} $$

This page was created using