Question

afla nr abcd stiind ca:abcd+bcd+cd+d=1986

Answer 1

abcd+bcd+cd+d=1986
1000a+100b+10c+d+100b+10c+d+10c+d+d=
1986
1000a+200b+30c+4d=1986
a =1
b=4
1800+ 30c+4d=1986/ - 1800
30c+4d= 186
c= 1,2,3,4,5,6,dar nu toate convin
30+4d=186 = 4d=156/ :4 = d=39
60+4d=186. = 4d=126. nu convine
90+4d=186 = 4d=96/: 4. = d= 24
120+4d=186 = 4d=66. nu convine
150+ 4d=186= 4d=36/:4. = d= 9
180+4d=186 = 4d=6 nu convine
raspunsul corect e 9 deoarece d poate avea doar o cifra.

150= 30 x c = c = 5

nr. este 1459

sper ca te-am ajutat si ca vei intelege

Answer 2

abcd +
bcd
cd
d
--------
1986

d + d + d + d = 4 × d = _6
==> 4 × 9 = 36
==> d = 9

c + c + c + 3 = _8
==> 3 × c + 3 = _8
==> 3 × 5 + 3 = 18
==> c=5

b + b + 1 = 9
==> 2 × b + 1 = 9
==> 2 × 4 + 1 = 9
==> b = 4

a = 1; b = 4; c = 5; d = 9 ==>

==> abcd = 1459

Verificare:
1459 + 459 + 59 + 9 = 1986