1.
2ab+3ba=577
200+10a+b+300+10b+a=577
11a+11b=77
a+b=7
a={1,2,3,4,5,6)
b={6,5,4,3,2,1}
numere sunt:16,25,34,43,52,61
2.
b=a+2
c-b=3
c=a+2+3=a+5
c={6,7,8,9}
a={1,2,3,4}
b={3,4,5,6)}
numerele sunt :136 , 247, 358, 469
3.a+b=36
b+c=57
a+c=51
2(a+b+c)=36+57+51=144
a+b+c=72
c=72-36=36
c-a-b=36-36=0
4.a+b+c=8511
a=b+1266 ⇒ b=a-1266
a=c-2055 ⇒ c=a+2055
a+a-1266+a+2055=8511
3a=8511-2055+1266
3a=7722
a=2574
b=2574-1266=1308
c=2574+2055=4629