问一题机井

evildoll

4. k is a 2-digit positive integer, the value of k is 6 times of the unit digit, what is the value of k? D
(1). the ten digit is 4 greater than unit digit.
(2). the sum of the two digits is a two-digit integer.

猫猫头

K=a+10b=6b==>a+4b=0

isenetlab12

the problem discription must be wrong since "the value of k is 6 times of the unit digit" means k<=54 then only 51 and 40 can meet the condition (1), but violate the "the value of k is 6 times of the unit digit" so the condition (1) may be the incorrect record; from condition (2), we can find 48 is the only value can meet the question. we can list all the numbers 19, 29,28,39,38,37,49,48,47,46 agree?

evildoll

en,i think it questionable
when suppose unit digit=b,ten digit=a
so 10a+b=6b
   a=b+4
then a=-4
faint