\[При\ a - b = 7:\]
\[\frac{(2a - 2b)^{2}}{1,4} = \frac{4 \cdot (a - b)^{2}}{1,4} = \frac{2 \cdot 7^{2}}{0,7} = \frac{2 \cdot 7}{0,1} =\]
\[= \frac{14}{0,1} = 140.\]