Răspuns:
b- c= (125 x 4 - 16 x 25): 2
b-c=(500-400):2
b-c=100:2
b-c=50
c: 1 = 100 - 3 (32 × 10 - 3 x99)
c:1=100-3(320-397)
c:1=100-3x23
c:1=100-69
c:1=31
c=31x1
c=31
b-c=50
b-31=50
b=50+31
b=81
a=bx42
a=81x42
a=3402
a-b x c+b
3402-81x31+81=
3402-2511+81
891+81=972