a=bancnote de 10 lei
2a=bancnote de 25 lei
b=bancnote de 100 lei
a+2a+b=152
3a+b=152 b=152-3a
10×a+25×2a+100×b=5600
10a+50a+100b=5600
60a+100b=5600
6a+10b=560
6a+10(152-3a)=560
6a+1520-30a=560
24a=960
a=40 bancnote de 10 lei
2a=2×40=80 bancnote de 25 lei
152-40-80=152-120=32 bancnote de 100 lei