Which statement is true for EVERY pair of positive integers a and b?

Since HCF(a, b) $x$ LCM(a, b) = $axb$ and the HCF divides both a and $b$, the HCF always divides the LCM. The others fail: if $a=b$ then HCF = LCM, so the HCF is not always strictly smaller; LCM = $axb$ only when a and $b$ are co-prime; and for $a=4,b=6$ we get HCF + LCM = 2 + 12 = 14 while $a+b=10$.