求PREP-DS-1-167 解

jesuisdesole

167.
                16626-!-item-!-187;#058&010859

If x, y, and z are integers and xy + z is an odd integer, is x an even integer?

 

(1) xy + xz is an even integer.

 

(2) y + xz is an odd integer.

没思路

求教....