{a,b,c} dp {2,4,7}
dp=direct proportional
[tex] \frac{a}{2} = \frac{b}{4} = \frac{c}{7} = k \\ = > \frac{a}{2} = k = > a = 2k \\ \frac{b}{4} = k = > b = 4k \\ \frac{c}{7} = k = > c = 7k[/tex]
a+b+c=169
2k+4k+7k=169
13k=169
k=169:13
k=13 => a=2•13=26
b=4•13=52
c=7•13=91
