1] Całkowitymi dzielnikami liczby -8 są [tex]x\in[/tex] {-8; -4; -2; -1; 1; 2; 4; 8}, gdzie [tex]x\in Z[/tex]
2] [tex]7\cdot(-4)-2\cdot(-3)\cdot(-5)=-28-2\cdot3\cdot5=-28-30=-(-28+30)=-58[/tex]
3] [tex]2\frac{2}{9}-3\frac{5}{6}+5\frac{1}{3}=2\frac{4}{18}-3\frac{15}{18}+5\frac{6}{18}=\\ \\ -(3\frac{15}{18}-2\frac{4}{18})+5\frac{6}{18} =1\frac{11}{18} +5\frac{4}{18}=6\frac{15}{18}=5\frac{5}{6} [/tex]
4] [tex]3\frac{1}{2}-3\frac{1}{6}:(-2\frac{1}{9})=3\frac{1}{2}+\frac{19}{6} \cdot\frac{9}{19}=3\frac{1}{2} +\frac{3}{2} =3\frac{1}{2}+1\frac{1}{2}=5 [/tex]
5] [tex]\sqrt{4}=\sqrt{2^2}=2 [/tex] oraz [tex]\sqrt{9}=\sqrt{3^2}=3 [/tex] dlatego liczbami niewymiernymi, są liczby {[tex]\sqrt{2};\sqrt{3} ;\sqrt{8}; \sqrt{10} [/tex] }
6]
[tex]\sqrt{(-9)^2}=\sqrt{81} =9[/tex]
[tex]\sqrt{25}\cdot0,36 =5\cdot0,36=1,8[/tex]
[tex]\sqrt{6}\cdot \sqrt{1,5}=\sqrt{6\cdot1,5}=\sqrt{9}=3 [/tex]
[tex]3\sqrt{8}:729=3\cdot2\sqrt{2}:729=6\sqrt{2}:(3\cdot243)=\frac{2\sqrt{8} }{243} [/tex]
[tex]3\sqrt{-27} =3\cdot(-3)=-9[/tex]
natomiast [tex]3\sqrt{-3} [/tex]∉ R <- nie można obliczyć
7]
[tex]\frac{3}{5\sqrt{15} } \cdot\frac{\sqrt{15}}{\sqrt{15}} =\frac{3\sqrt{15}}{5\cdot15}=\frac{\sqrt{15}}{25} [/tex]
[tex]\frac{2}{3\sqrt{5} } \cdot\frac{\sqrt{5}}{\sqrt{5}} =\frac{2\sqrt{5}}{3\cdot5}=\frac{2\sqrt{5}}{15} [/tex]
8] [tex]log_u2+log_u8=log_u(2\cdot8)=log_u16[/tex]
9] 6,7%=0,067 oraz 50 promili to 5% = 0,05