v_{v a r i} = \frac{A B \cdot \frac{3}{2}}{t} = \frac{10 c m \cdot \frac{3}{2}}{5 s} = 3 \frac{c m}{s}

${v_{vari} =\dfrac{ AB\cdot\dfrac{3}{2}}{t}=\dfrac{ 10\mathrm{cm}\cdot\dfrac{3}{2}}{ 5\mathrm{s}}= 3\frac{\mathrm{cm}}{\mathrm{s}}}$

Error