Răspuns :
Determinati numerele de forma abc stiind ca abc = 7 x 100 + 8x 10 + 1
a=7, b=8, c=1
781 = 7 x 100 + 8x 10 + 1
Determinati cifrele a.b.c stiind ca 634 = a x100 + b x10 + c
a=6, b=3, c=4
634 =6 x100 + 3 x10 + 4
Determinati cifrele a,b,b,d sriind ca 4a5c = bx1000 + 3 x 100 + d x10 + 9
a=3, b= 4, c=9, d=5
4359 = 4x1000 + 3 x 100 + 5 x10 + 9
a) abc = 7 x 100 + 8 x 10 + 1 = 781 ⇒ a = 7; b = 8 si c = 1
b) 634 = a × 100 + b × 10 + c
634 = 6 × 100 + 3 × 10 + 4 ⇔ a = 6; b = 3 si c = 4
c) 4a5c = b × 1 000 + 3 × 100 + d × 10 + 9
4 × 1 000 + 3 × 100 + 5 × 10 + 9 = 4 000 + 300 + 50 + 9 = 4 359
⇔ a = 3; b = 4; d = 5 si c = 9