Question

demonstrati numerele naturale x si y stiind ca 3x+5y=
25

Answer 1

DETERMINATI  .etc
3x=25-5y
x=(25-5y)/3

y=0  x=25/3∉N
y=1  x=20/3∉N
y=2; x=15/3=5  SOLUTIE
y=3 x=10/3∉N
y=4 x=5/3∉N
y=5 x=0 SOLUTIE

deci (x;y)∈{(5;2);(0;5)}