Răspuns:
[tex]a,b,c .d.p. cu 5,7,12 = > a/5=b/7=c/12=k\\ \\a=5k;b=7k;c=12k\\\\5k+7k+12k=252\\\\24k=252= > k=252:24= > k=10,5\\\\a=5*10,5= > a=52.5\\\\b=7*10,5= > b=73,5\\\\c=12*10,5= > c=126\\\\\\a/5=b/7= > b=(7a/5)^{20} = > b=140a/100= > b.reprezinta-140.la.suta.din.a[/tex]