Question 64681
(2x-y=-1)3
6x-3y=-3       ------------------------1
6x+3y=0        -------------------------2
subtract2 from1
change the sign
-6y=-3
y=3/6
y=1/2
2x-y =-1
substitute the value of y in this equation
2x-1/2 =-1
4x-1=-2
4x=-2+1
4x=-1
x=-1/4