Question

1.
x - 2y = -25
3x - y = 0

Answer 1

x-2y=-25.......i

(3x-y=0)2

6x-2y=0......ii

now solving eq i and ii

x-2y=-25

- 6x+2y=0

here -2y and 2y are subtracted

or -5x =-25

or x=5.

now in eq i

5-2y=-25

or (5+25)/2=y

or y =15