Question

sa se gaseasca toate numerele de forma xy17 stiind ca xy+yx=77.

Answer 1

xy+yx=77:

x=4=>y=3,43+34=77=>4317,
x=3=>y=4,34+43=77=>3417,
x=2=>y=5,25+52=77=>2517,
x=5=>y=2,52+25=77=>5217,
x=1=>y=6,16+61=77=>1617,
x=6=>y=1,61+16=77=>6117.