Răspuns :
ab; cd ip cu 1/5 ; 1/7
ab * 1/5 = cd * 1/7 =k
ab/5=cd/7=k
ab=5k
cd=7k
ab+cd=36
5k+7k=36
12k=36
k=3
ab=5*3=15
cd=7*3=21
abcd=1521
ab * 1/5 = cd * 1/7 =k
ab/5=cd/7=k
ab=5k
cd=7k
ab+cd=36
5k+7k=36
12k=36
k=3
ab=5*3=15
cd=7*3=21
abcd=1521
[tex]\dfrac{\overline{ab}}{5}=\dfrac{\overline{cd}}{7}=\dfrac{\overline{ab}+\overline{cd}}{5+7}=\dfrac{36}{12}=3\Rightarrow \overline{ab}=15;\ \overline{cd}=21;\ \overline{abcd}=1521.[/tex]