Question

решите систему уравнений
{у-х=20
{2х-15у=-1

Answer 1

{y-x=20
{2x-15y=-1

{y=20+x
{2x-15(20-x)=-1

{y=20+x
{-13x=299

{y=20-23
{x=-23

{y=-3
{x=-23