a)[tex]\sqrt{49}+\sqrt{36}-\sqrt{25}=\\
=7+6-5=8[/tex]
b)[tex]2\sqrt{5}+3\sqrt{5}-\sqrt{5}=\\
=(2+3-1)\sqrt{5}=4\sqrt{5}[/tex]
c)[tex]3\sqrt{12}-\sqrt{147}+\sqrt{243}=\\
=3\sqrt{2^2\cdot3}-\sqrt{7^2\cdot3}+\sqrt{9^2\cdot3}=\\
=6\sqrt{3}-7\sqrt{3}+9\sqrt{3}=\\
=(6-7+9)\sqrt{3}=\\
=8\sqrt{3}[/tex]
d)[tex]3\sqrt{7}-2\sqrt{5}+3\sqrt{5}-\sqrt{7}\\
=(-2+3)\sqrt{5}+(3-1)\sqrt{7}=\\
=\sqrt{5}+2\sqrt{7}[/tex]
e)[tex]2\sqrt{18}-5\sqrt{8}-\sqrt{50}=\\=
2\sqrt{3^2\cdot2}-5\sqrt{2^2\cdot2}-\sqrt{5^2\cdot2}=\\
=6\sqrt{2}-10\sqrt{2}-5\sqrt{2}=\\
=(6-10-5)\sqrt{2}=\\
=-9\sqrt{2}[/tex]
f)[tex]\sqrt{18}+\sqrt{20}-2\sqrt{2}-3\sqrt{5}=\\
=\sqrt{3^2\cdot2}-2\sqrt{2}+\sqrt{2^2\cdot5}-3\sqrt{5}=\\
=3\sqrt{2}-2\sqrt{2}+2\sqrt{5}-3\sqrt{5}=\\
=(3-2)\sqrt{2}+(2-3)\sqrt{5}=\\
=\sqrt{2}-\sqrt{5}[/tex]
