9/16*(5 1/3х-4/15у)-7/23*(3 2/7х-2 4/21у)= 2х-31/60у
1) 9/16*(5 1/3х-4/15у)=
9/16*(16/3х-4/15у)=
3х-3/4*5у= 3х-3/20у
2) 7/23*(3 2/7х-2 4/21у)=
7/23*(23/7х- 46/21у) =
х-2/3у
3) 3х-3/20у - (х-2/3у)=
3х-3/20у - х+2/3у=
2х-9/60у + 40/60у=
2х-31/60у
{x-2y=4
{x*y=6
{x=4+2y
{(4+2y)y=6
{x=4+2y
{4y+2y^2-6=0 |:2
{x=4+2y
{y^2+2y-3=0
{x=4+2y
{y1=-3; y=1
{x1=-2; x2=6
{y1=-3; y2=1
ответ: (-2; -3) v (6; 1)