Question

Cистема рівнянь
7xy+y=16
7xy-x=13

Answer 1

{ 7xy+y=16
{ 7xy-x=13

{ 7xy=16-y
{ 7xy=13+x

{ x=3-y
{ 7y(3-y)=16-y

{ x=3-y
{ 7y^2 -22y+16=0

{ [y=17/7
  [y=5/7
{ x=3-y

{ [x=4/7
  [y=17/7
{ [x=16/7
  [y=5/7

Ответ: 4/7;17/7  или 16/7;5/7