Given the square of a-2ab-3b = 0 (AB is not equal to 0), then the value of a of B + B of a is 0

Given the square of a-2ab-3b = 0 (AB is not equal to 0), then the value of a of B + B of a is 0

a²-2ab-3b²=0;
(a-3b)(a+b)=0;
A = 3B or a = - B;
a/b+b/a=(a²+b²)/(ab)
When a = 3b, the original formula = (10b & # 178;) / (3b & # 178;) = 10 / 3;
When a = - B, the original formula = (2B & # 178;) / (- B & # 178;) = - 2;