Vgln. eerste graad (reeks 3)

Reeks met haakjes

\(5(x+4)=-1+(12+x)\)

\(\begin{align} & \color{red}{5} (x+4)& = & -1 \color{red}{+} (12+x) \\\Leftrightarrow & 5x+20& = &-1+12+x \\\Leftrightarrow & 5x \color{red}{+20} & = &11 \color{red}{+x} \\\Leftrightarrow & 5x \color{red}{+20} \color{blue}{-20} \color{blue}{-x} & = &11 \color{red}{+x} \color{blue}{-x} \color{blue}{-20} \\\Leftrightarrow & 5x-x& = &11-20 \\\Leftrightarrow & 4x& = &-9 \\\Leftrightarrow & \frac{4x}{ \color{red}{4} }& = &\frac{-9}{ \color{red}{4} } \\\Leftrightarrow & x = \frac{-9}{4} & & \\ & V = \left\{ \frac{-9}{4} \right\} & \\\end{align}\)