2ug.\frac{2 \mathrm{u}}{\mathrm{g}} .g2u.
u22 g\frac{u^{2}}{2 \mathrm{~g}}2 gu2
ug\frac{\mathrm{u}}{\mathrm{g}}gu
u2 g\frac{\mathrm{u}}{2 \mathrm{~g}}2 gu