Răspuns :
Ax42+720-720:9=1.060
Ax42+720-80=1.060
Ax42+720=1.060+80
Ax42+720=1.140
Ax42=1.140-720
Ax42=420
A=420:42
A=10
Ax42+720-80=1.060
Ax42+720=1.060+80
Ax42+720=1.140
Ax42=1.140-720
Ax42=420
A=420:42
A=10