Răspuns :
n- numarul scris de Sorin
nx4=A
A+36=B
Bx3=C
C+292=D
D:5=200
Pur si simplu facem drumul invers. ABCD sunt noile reziltate obtinute dupa fiecare operatie
D:5=200 => D=200x5=> D=1000
C+292=1000=> C=1000-292=> C=708
Bx3=708 => B=708:3=> B=236
A+36=236=> A=236-36=> A=200
nx4=200=> n=200:4=> n=50
nx4=A
A+36=B
Bx3=C
C+292=D
D:5=200
Pur si simplu facem drumul invers. ABCD sunt noile reziltate obtinute dupa fiecare operatie
D:5=200 => D=200x5=> D=1000
C+292=1000=> C=1000-292=> C=708
Bx3=708 => B=708:3=> B=236
A+36=236=> A=236-36=> A=200
nx4=200=> n=200:4=> n=50
Notăm numărul necunoscut x.
{[(x·4+36)·3]+292}:5=200 (Mersul invers, se inversează şi semnul)
[(x·4+36)·3]+292=1000
(x·4+36)·3 = 1000-292 = 708
x·4+36=708:3=236
x·4+36=236
x·4=236-36
x·4=200
x=200:4=50
x=50
{[(x·4+36)·3]+292}:5=200 (Mersul invers, se inversează şi semnul)
[(x·4+36)·3]+292=1000
(x·4+36)·3 = 1000-292 = 708
x·4+36=708:3=236
x·4+36=236
x·4=236-36
x·4=200
x=200:4=50
x=50