Vgln. eerste graad (reeks 1)

Bepaal de waarde van x.

\(x-15=-3\)

\(\begin{align} & x \color{red}{-15}& = &-3 \\\Leftrightarrow & x \color{red}{-15}\color{blue}{+15} & = &-3\color{blue}{+15} \\\Leftrightarrow &x & = &12\\\Leftrightarrow & \color{red}{}x & = &12\\\Leftrightarrow & \frac{\color{red}{}x}{ \color{blue}1} & = & 12 \\\Leftrightarrow & \color{green}{ x = 12 } & & \\ & V = \left\{ 12 \right\} & \\\end{align}\)