Originally Posted by thegarden Proofs required for the following divisibility rules: a|1 implies a= plus or minus 1a|b and b|a IF AND ONLY IF (IFF) a= plus or minus ba|b IFF -a|b IFF a|(-b) IFF (-a)(-b)Let b>0. If a|b implies a is less than or equal to bSorry for not inserting mathematical signs, new to the forum so just finding my way around, many thanks. Use definition of division. I do the first one. .
And second one , .
Thus, (assuming ).