(х,у)=(5,-2)
Объяснение:
{х=31/7-2/7у
{4х-5у=30
4(31/7-2/7у)-5у=30
у=-2
х=31/7-2/7×(-2)
х=5
{7×5+2×(-2)=31
{4×5-5×(-2)=30
{31=31
{30=30
(х,у)=(5,-2)
Объяснение:
{х=31/7-2/7у
{4х-5у=30
4(31/7-2/7у)-5у=30
у=-2
х=31/7-2/7×(-2)
х=5
(х,у)=(5,-2)
{7×5+2×(-2)=31
{4×5-5×(-2)=30
{31=31
{30=30
(х,у)=(5,-2)