Ответ:

1) (x,y) = (2, -1)

2) (x,y) =  (10, -35/2)

Объяснение:

1)

(х=5/2 + 1/2y
(3x + 5y = 1

3(5/2+1/2y) + 5y = 1

y= - 1

x = 5/2 + 1/2 * (-1)

x = 2

(x,y) = (2, -1)

(4*2 - 2*(-1) = 10

(3*2 + 5 * (-1) = 1

(10=10

(1=1

2)

(2y = - 25 - x

(3x + 2y = -5

3x - 25 - x = -5

x = 10

3*10+2y= -5

y = - 32/2

(x,y) = (10, -35/2)

(10+2 * (-35/2) = -25

(3*10+2*(-35/2)= -5

(-25 = -25

(-5 = -5