if x and y are positive integers and y ≠ 1 , then xy ( y − 1 ) is
"expression is xy ( y - 1 ) . we can ignore x and only work with y . if y = even - > entire expression is even since anything multiplied by even is even if y = odd , y - 1 - > even - > entire expression is even since anything multiplied by even is even hence , entire expression will always be even . answer ( a ) ."
add(1, const_1)