a = 14 si b + c = 56
34 b + 34 c - 56 a = 1 120
= 34 × ( b + c ) - 56 × 14 =
= 34 × 56 - 56 × 14 =
= 56 × ( 34 - 14 ) =
= 56 × 20 =
= 1 120
A=14,B+C=56
34B+34C-56A=?
B+C=56/*34
34B+34C=34*56=1904
56A=14*56
56A=784
34B+34C-56A=1904-784=1120
Raspuns:1120