b*4*2=64 ; b=64:4*2; b=8
a:9=6 ; a=6*9; a=54
b*4*2=32; b*8=32; b=32:8; b=4
3............ 21; 3*C= 21; C= 21:3; 1C= 7 lei, daca 1C = 7 lei, atunci 7C= 7*7=49 lei
7..........x
x= 7*21/3; x=49
8.......56
5........x
x= 56*8/5,; x=35
6x4 =24
24:3=28
1+3+5+7+9=25
25:5=5