1. [tex] \frac{a}{2}= \frac{b}{5} = \frac{c}{7}= \frac{d}{10}=k \\ a=2k ; b=5k ; c=7k ; d=10k \\ a+b+c+d=360 \\ 2k+5k+7k+10k=360 \\ 24k=360 \\ k=15 \\ a=30;b=75;c=105;d=150 [/tex]
2. [tex]0,1(6)= \frac{1}{6}; 0,25= \frac{1}{4};0,1(1)= \frac{1}{9} [/tex]
[tex]a* \frac{1}{6} =c* \frac{1}{4} =d* \frac{1}{9} \\ \frac{a}{6}= \frac{c}{4}=\frac{d}{9}=k \\ a=6k;c=4k;d=9k \\ 6k+75+4k+9k=19k+75=360;19k=285;k=15 \\ a=90;c=60;d=135[/tex]
3. [tex] \frac{b}{5}=\frac{c}{6}=\frac{d}{7} =k;b=5k;c=6k;d=7k \\ 90+5k+6k+7k=90+18k=360 \\ 18k=270;k=15;b=75;c=90;d=105 [/tex]