Question

{3х+ y=2
{x2-xy+6y=-4
решите пж

Answer 1

3x + y = 2
X^2 - xy + 6y = - 4
••••••••••••••
y = 2 - 3x
X^2 - x( 2 - 3x ) + 6( 2 - 3x ) = - 4
X^2 - 2x + 3x^2+ 12 - 18x = - 4
4x^2 - 20x + 16 = 0
4( x^2 - 5x + 4 ) = 0
D = 25 - 16 = 9 = 3^2
X1 = ( 5 + 3 ) : 2 = 4
X2 = ( 5 - 3 ) : 2 = 1
••••••
y = 2 - 3x
y1 = 2 - 12 = - 10
y2 = 2 - 3 = - 1
ОТВЕТ ( 4 ; - 10 ) ; ( 1 ; - 1 )