Question

a, (b) + b, (a)= 11, (1)​

Answer 1

a,(b)+b,(a)=11,(1)

(ab-a)/9+(ba-b)/9=(111-11)/9

(10a+b-a+10b+a-b)/9=100/9

(10a+10b)/9=100/9

10a+10b=100

10(a+b)=100

a+b=10 cu conditia ca a,b=cifre

deci (a;b)={(9;1);(8;2);(7;3);(6;4);(5;5);(4;6);(3;7);(2;8);(1;9)}