Question

efectuati
(ab+bc+ca) / (a+b+c)=

Answer 1

$\frac{ab+bc+ca}{a+b+c}=\frac{10a+b+10b+c+10c+a}{a+b+c}=\frac{11a+11b+11c}{a+b+c}=\frac{11*(a+b+c)}{a+b+c}=11$