а)
{ x+y = 4 ×5
{4x-5y= 7
{5x-5y= 20
9x= 27
x= 3
4×3-5y= 7
-5y= 7-12= -5
y=1
b)
{ x-y = 6 ×(-2)
{ 5x-2y = -3
{ -2x+2y= -12
{ 5x-2y= -3
3x= -15
x= -5
5×(-5)-2y= -3
-2y= -3+25=22
y = -11
а)
{ x+y = 4 ×5
{4x-5y= 7
{5x-5y= 20
{4x-5y= 7
9x= 27
x= 3
4×3-5y= 7
-5y= 7-12= -5
y=1
b)
{ x-y = 6 ×(-2)
{ 5x-2y = -3
{ -2x+2y= -12
{ 5x-2y= -3
3x= -15
x= -5
5×(-5)-2y= -3
-2y= -3+25=22
y = -11