Question

ab+ac+a=165 b+c=10 aflati pe "a"

Answer 1

$ab+ac+a=165 \\ b+c=10 \\ a=? \\ a(b+c)+a=165 \\ 10a+a=165 \\ 11a=165 \\ a=165:11 \\ \boxed{a=15}$

Answer 2

a*(b+c+1)=165
a*11=165 =>a=165:11=15