Proste o równaniach 𝑦 = 2/3x − 3 oraz 𝑦 = (2𝑚 − 1)𝑥 + 1 są prostopadłe, gdy

$\displaystyle m=- \frac{5}{4}$\displaystyle m=- \frac{5}{4}

$\displaystyle m=- \frac{1}{4}$\displaystyle m=- \frac{1}{4}

$\displaystyle m= \frac{5}{6}$\displaystyle m= \frac{5}{6}

$\displaystyle m= \frac{5}{4}$\displaystyle m= \frac{5}{4}