Vgln. eerste graad (reeks 3)

Reeks met haakjes

\(3(2x+4)=7-(12+x)\)

\(\begin{align} & \color{red}{3} (2x+4)& = & 7 \color{red}{-} (12+x) \\\Leftrightarrow & 6x+12& = &7-12-x \\\Leftrightarrow & 6x \color{red}{+12} & = &-5 \color{red}{-x} \\\Leftrightarrow & 6x \color{red}{+12} \color{blue}{-12} \color{blue}{+x} & = &-5 \color{red}{-x} \color{blue}{+x} \color{blue}{-12} \\\Leftrightarrow & 6x+x& = &-5-12 \\\Leftrightarrow & 7x& = &-17 \\\Leftrightarrow & \frac{7x}{ \color{red}{7} }& = &\frac{-17}{ \color{red}{7} } \\\Leftrightarrow & x = \frac{-17}{7} & & \\ & V = \left\{ \frac{-17}{7} \right\} & \\\end{align}\)