Question

Aflați numărul abcd care verifică egalitatea: abcd+bcd+cd+d=3102

Answer 1

a=2...(2000)
b=5...(500)
c=3...(30)
d=3....(3)

2533+533+33+3=
=3066+36
=3102

......................................................................................................
a*1000+2b*100+3c*10+4d=3102

3c*10+4d=102...=> 3c=102-3*4....=3c=102-12....=>3c=90...=>c=30
3c*30+4d=102...=> 4d=102-90.....=>4d=12....=>d=12:4....=>d=4
a=3000-1000
a=2000
b=(3000-2000):2
b=1000:2
b=500

1*2000+2*500+3*30+4*3=
=2000+1000+90+12
=3000+102
=3102

=> abcd=2000+500+30+3
              =2533
     bcd  =  500+30+3
             =533
        cd =30+3
             =33
          d=3

2533+533+33+3=3102