Question Number 64085 by Rio Michael last updated on 12/Jul/19
$${please}\:{just}\:{read}\:{equation}\:{of}\:{a}\:{line}\:{and}\:{a}\:{plane}\:{in}\:{vectors}. \\ $$$${i}\:{don}'{t}\:{understand}\: \\ $$$$\:\:\left(\boldsymbol{{r}}−\boldsymbol{{a}}\right)×\boldsymbol{{b}}=\mathrm{0}\:\:?? \\ $$