[tex]A)\\0,2(\sqrt{50}-\sqrt{75})=0,2(\sqrt{25\cdot2}-\sqrt{25\cdot3})= 0,2(5\sqrt{2}-5\sqrt{3}) = 0,2\cdot5(\sqrt{2}-\sqrt{3})=\\\\\approx1,41 -1,73 \approx-0,32\approx-0,3[/tex]
[tex]B)\\(\sqrt{48}+\sqrt{32}):40 = (\sqrt{16\cdot3}+\sqrt{16\cdot2}):40 = (4\sqrt{3}+4\sqrt{2}):40 =\\\\= [4(\sqrt{3}+\sqrt{2})]:40\approx[4(1,73+1,41})]:40 \approx(4\cdot3,14):40 \approx 12,56:40\approx0,3[/tex]
[tex]C)\\3(\sqrt{\frac{1}{2}})+\sqrt{2}\approx3\cdot\frac{\sqrt{2}}{2}+1,41\approx3\cdot0,705+1,41\approx2,115+1,41\approx3,525\approx3,5[/tex]
