C-09-Q050mediumsingle_mcqFor a>0, b>0a > 0,\, b > 0a>0,b>0 and r,s∈Qr,s \in Qr,s∈Q, ar⋅asa^r \cdot a^sar⋅as equals:aar−sa^{r-s}ar−sbarsa^{rs}arsc