5x−4y=−10 −4x+5y=8 solve system of equations

5y = 4x + 8 and y = 4x/5 + 8/5

   {5x−4y=−10  ⇒ 5x = 4y-10  ⇒  x=(4y-10)/5  ⇒  x = 0.8y - 2
​   {-4x+5y=8

-4(0.8y-2) + 5y = 8
-3.2y + 8 + 5y = 8
1.8y = 8 - 8
1.8y = 0
y = 0

5x−4·0=−10
5x = -10
x = -10/5
x = -2

Your answer is (-2, 0)