Question

abc-cba=693
abc = 693 + cba
Sa se afle abc si cba dau 47 de puncte

Answer 1

abc - cba = 693
100×a + 10×b + c - 100×c - 10×b - a = 693
99×a - 99×c = 693
99×(a-c) = 693
a-c = 693:99
a-c = 7
9-2 = 7
8-1 = 7

caz1:
a = 9
b = 0
c = 2
==> abc = 902
902 - 209 = 693

caz2:
a = 8
b = 0
c = 1
==> abc = 801
801 - 108 = 693

abc = { 902; 801}
cba = {209; 108}