A = 100 +10x +6y si (5x +3y =27)×2⇒10x +6y = 54
A = 100 + 54 = 154. deci A=154
4 +2x +7y =15 si B = 20 +10x +35y
( 4 +2x +7y =15 )×5⇒20 + 10x +35 = 75⇒B = 75
C = 3×(x + 5y) - 42 = 3×23 - 42 = 27 ⇒C = 27
D = 4×(3x- 2y) = 4×(18+4) = 4×22 = 88 ⇒D=88
Se considera numarul A=1234567....9899100. Determinati numarul cifrelor numarului A