Question

Ответить на 3 примера

Answer 1

Ответ:

(x, y) = (2, 4); (x, y) = (3, 0); (x, y) = (-1, -1)

Пошаговое объяснение:

1) $\left \{ {{3x-2y=-2} \atop {5x+2y=18}} \right.$

$\left \{ {{3x-2y=-2} \atop {2y=18-5x}} \right.$

3x-(18-5x)=-2

x=2

2y=18-5*2

y=4

(x, y) = (2, 4)

$\left \{ {{3*2-2*4=-2} \atop {5*2+2*4=18}} \right.$

$\left \{ {{-2=-2} \atop {18=18}} \right.$

2) $\left \{ {{3x+2y=9} \atop {-3x-5y=-9}} \right.$

$\left \{ {{3x=9-2y} \atop {-3x-5y=-9}} \right.$

-(9-2y)-5y=-9

y=0

-3x-5*0=-9

x=3

(x, y) = (3, 0)

$\left \{ {{3*3+2*0=9} \atop {-3*3-5*0=-9}} \right.$$\left \{ {{9=9} \atop {-9=-9}} \right.$

3) $\left \{ {{-4x+5y=-1} \atop {2x-5y=3}} \right.$

$\left \{ {{5y=-1+4x} \atop {2x-5y=3}} \right.$

2x-(-1+4x)=3

x=-1

2*(-1)-5y=3

y=-1

(x, y) = (-1, -1)

$\left \{ {{-4*(-1)+5*(-1)=-1} \atop {2*(-1)-5*(-1)=3}} \right.$

$\left \{ {{-1=-1} \atop {3=3}} \right.$