13) - 3x - 4y = 8

-4x - 3y=6

x = 0, y = - 2

Step-by-step explanation:

-3x - 4y = 8 (1)

-4x - 3y=6 (2)

Multiply (1) by - 4 and (2) by - 3, we have:

12x + 16y = - 32 (3)

12x + 9y = - 18 (4)

Subtract (4) from (3), we have:

(12x + 16y) - (12x + 9y) = - 32 - (-18)

7y = - 14

=> y = - 2

Replace y with - 2 in (3), we have x = 0