Vgln. eerste graad (reeks 1)

Bepaal de waarde van x.

\(-5x-7=-9\)

\(\begin{align} & -5x \color{red}{-7}& = &-9 \\\Leftrightarrow & -5x \color{red}{-7}\color{blue}{+7} & = &-9\color{blue}{+7} \\\Leftrightarrow &-5x & = &-2\\\Leftrightarrow & \color{red}{-5}x & = &-2\\\Leftrightarrow & \frac{\color{red}{-5}x}{ \color{blue}-5} & = & \frac{-2}{-5} \\\Leftrightarrow & \color{green}{ x = \frac{2}{5} } & & \\ & V = \left\{ \frac{2}{5} \right\} & \\\end{align}\)