I need find x and y by elimination or by substitution... But how?

It is easiest to do elimination

4x-y=-5

(-2x+3y=10)2

4x-y=-5

-4x+6y=20

5y=15

y=3

4x-1(3)=-5

4x-3=-5

   +3 +3

4x=-2

x=-1/2

answer: (-1/2, 3)

Thanks, TR.....I'll do it by substitution just so you can have two different methods to look at

4x-y=-5   →    y  = 4x + 5     (1)

-2x+3y=10   (2)

Substitute  (1)  into (2)  for y

-2x + 3(4x + 5)   = 10    simplify

-2x + 12x + 15  = 10

10x + 15  = 10      subtract 15 from both sides

10x  = -5           divide both sides by 1

x = -5/10  = -1/2

And using (1)    y = 4(-1/2)  + 5   =  -2 + 5   =  3