Ответ:\(\sqrt{a-b}=\sqrt{-0.29-(-0.78)}=\sqrt{0.49}=0.7\).\(\sqrt{a-b}=\sqrt{\frac14-\left(-\frac49\right)}=\sqrt{\frac14+\frac49}=\sqrt{\frac{25}{36}}=\frac56\).Ответ: 1) 0,7; 2) \(\frac56\).