Question

AJUTORRRRRRRRRRRRRRRRRRRRRRRRRRRRRR!!​

Answer 1

2•abcd+274=bcda

2(1000a+bcd)+274=bcd•10+a

2000a+2•bcd+274=10•bcd+a

1999a+274=8•bcd

           par    par

=>a este cifra para

1999•a+274≤8•999

1999•a≤7992-274=7718=> a<4

=> a=2

1999•2+274=8•bcd   /:2

1999+137=4•bcd

2136=4•bcd

bcd=2136:4

bcd=534

abcd=2534

verificare: mutand prima cifra a nr. 2534=> 5342

2•2534+274=5341  (A)