the three possible answers are 428, 356, and 284. All are less than 500, all have a units digit twice the hundreds digit, and all have 14 as a sum of digits.
so xyz=number z=2x x+y+z=14 subsitute z=2x into x+y+z=14 x+y+(2x)=14 3x+y=14 number must be 3 digit and less thaan 500 since the tens digit's max is 9 then z+x≥14-9 z=2x 3x≥5 x max=5 because 500 is max so x could be 2,3,4 so
