\(\left(\frac27\cdot\frac14-\frac13\cdot\frac27\right):\left(\frac27\cdot\frac39-\frac27\cdot\frac25\right)=\frac27\left(\frac14-\frac13\right):\frac27\left(\frac39-\frac25\right)=\frac54,B\frac34\frac{\left(\frac15-\frac27-\frac13+\frac27\right)}{\frac15\left(\frac27+\frac13\right)-\frac13\left(\frac27+\frac13\right)}=\frac{\frac34\left(\frac15-\frac13\right)}{\left(\frac15-\frac13\right)\left(\frac27+\frac13\right)}=\frac{63}{52}\)

\(\left(\frac27\cdot\frac14-\frac13\cdot\frac27\right):\left(\frac27\cdot\frac39-\frac27\cdot\frac25\right)=\frac27\left(\frac14-\frac13\right):\frac27\left(\frac39-\frac25\right)=\frac54,B\frac34\frac{\left(\frac15-\frac27-\frac13+\frac27\right)}{\frac15\left(\frac27+\frac13\right)-\frac13\left(\frac27+\frac13\right)}=\frac{\frac34\left(\frac15-\frac13\right)}{\left(\frac15-\frac13\right)\left(\frac27+\frac13\right)}=\frac{63}{52}\)

\(\left(\frac27\cdot\frac14-\frac13\cdot\frac27\right):\left(\frac27\cdot\frac39-\frac27\cdot\frac25\right)=\frac27\left(\frac14-\frac13\right):\frac27\left(\frac39-\frac25\right)=\frac54,B\frac34\frac{\left(\frac15-\frac27-\frac13+\frac27\right)}{\frac15\left(\frac27+\frac13\right)-\frac13\left(\frac27+\frac13\right)}=\frac{\frac34\left(\frac15-\frac13\right)}{\left(\frac15-\frac13\right)\left(\frac27+\frac13\right)}=\frac{63}{52}\)

\(\left(\frac27\cdot\frac14-\frac13\cdot\frac27\right):\left(\frac27\cdot\frac39-\frac27\cdot\frac25\right)=\frac27\left(\frac14-\frac13\right):\frac27\left(\frac39-\frac25\right)=\frac54,B\frac34\frac{\left(\frac15-\frac27-\frac13+\frac27\right)}{\frac15\left(\frac27+\frac13\right)-\frac13\left(\frac27+\frac13\right)}=\frac{\frac34\left(\frac15-\frac13\right)}{\left(\frac15-\frac13\right)\left(\frac27+\frac13\right)}=\frac{63}{52}\)

\(\left(\frac27\cdot\frac14-\frac13\cdot\frac27\right):\left(\frac27\cdot\frac39-\frac27\cdot\frac25\right)=\frac27\left(\frac14-\frac13\right):\frac27\left(\frac39-\frac25\right)=\frac54,B\frac34\frac{\left(\frac15-\frac27-\frac13+\frac27\right)}{\frac15\left(\frac27+\frac13\right)-\frac13\left(\frac27+\frac13\right)}=\frac{\frac34\left(\frac15-\frac13\right)}{\left(\frac15-\frac13\right)\left(\frac27+\frac13\right)}=\frac{63}{52}\)

\(\left(\frac27\cdot\frac14-\frac13\cdot\frac27\right):\left(\frac27\cdot\frac39-\frac27\cdot\frac25\right)=\frac27\left(\frac14-\frac13\right):\frac27\left(\frac39-\frac25\right)=\frac54,B\frac34\frac{\left(\frac15-\frac27-\frac13+\frac27\right)}{\frac15\left(\frac27+\frac13\right)-\frac13\left(\frac27+\frac13\right)}=\frac{\frac34\left(\frac15-\frac13\right)}{\left(\frac15-\frac13\right)\left(\frac27+\frac13\right)}=\frac{63}{52}\)

\(\left(\frac27\cdot\frac14-\frac13\cdot\frac27\right):\left(\frac27\cdot\frac39-\frac27\cdot\frac25\right)=\frac27\left(\frac14-\frac13\right):\frac27\left(\frac39-\frac25\right)=\frac54,B\frac34\frac{\left(\frac15-\frac27-\frac13+\frac27\right)}{\frac15\left(\frac27+\frac13\right)-\frac13\left(\frac27+\frac13\right)}=\frac{\frac34\left(\frac15-\frac13\right)}{\left(\frac15-\frac13\right)\left(\frac27+\frac13\right)}=\frac{63}{52}\)

\(\left(\frac27\cdot\frac14-\frac13\cdot\frac27\right):\left(\frac27\cdot\frac39-\frac27\cdot\frac25\right)=\frac27\left(\frac14-\frac13\right):\frac27\left(\frac39-\frac25\right)=\frac54,B\frac34\frac{\left(\frac15-\frac27-\frac13+\frac27\right)}{\frac15\left(\frac27+\frac13\right)-\frac13\left(\frac27+\frac13\right)}=\frac{\frac34\left(\frac15-\frac13\right)}{\left(\frac15-\frac13\right)\left(\frac27+\frac13\right)}=\frac{63}{52}\)

\(\left(\frac27\cdot\frac14-\frac13\cdot\frac27\right):\left(\frac27\cdot\frac39-\frac27\cdot\frac25\right)=\frac27\left(\frac14-\frac13\right):\frac27\left(\frac39-\frac25\right)=\frac54,B\frac34\frac{\left(\frac15-\frac27-\frac13+\frac27\right)}{\frac15\left(\frac27+\frac13\right)-\frac13\left(\frac27+\frac13\right)}=\frac{\frac34\left(\frac15-\frac13\right)}{\left(\frac15-\frac13\right)\left(\frac27+\frac13\right)}=\frac{63}{52}\)

\(\left(\frac27\cdot\frac14-\frac13\cdot\frac27\right):\left(\frac27\cdot\frac39-\frac27\cdot\frac25\right)=\frac27\left(\frac14-\frac13\right):\frac27\left(\frac39-\frac25\right)=\frac54,B\frac34\frac{\left(\frac15-\frac27-\frac13+\frac27\right)}{\frac15\left(\frac27+\frac13\right)-\frac13\left(\frac27+\frac13\right)}=\frac{\frac34\left(\frac15-\frac13\right)}{\left(\frac15-\frac13\right)\left(\frac27+\frac13\right)}=\frac{63}{52}\)