Question

The GCD(a, b) = 9, the LCM(a, b)=378. Find the least possible value of a+b

Answer 1

`\text{lcm}(a,b)=\fraca\cdot b{\text{gcd}(a,b)}\\\\378=(|a\cdot b|)/(9)\\\\|a\cdot b|=42\\\\a\cdot b=-42 \vee a\cdot b=42`

So, the least value is -42