(1/2-2/3+3/4):14/12=
=(6/12-8/12+9/12):7/6=
=(-2/12+9/12):7/6=
=7/12:7/6=
=7/12×6/7=1/2
(1supra2-2supra3+3supra4):14supra12=
[tex]\it \Big(\dfrac{^{6)}1}{\ 2}-\dfrac{^{4)}2}{\ 3}+\dfrac{^{3)}3}{\ 4}\Big):\dfrac{14}{12}=\dfrac{6-8+9}{12}:\dfrac{14}{12}=\dfrac{7}{12}\cdot\dfrac{12}{14}=\dfrac{\ 7^{(7}}{14}=\dfrac{1}{2}[/tex]
