Question 62900
E1:  x+2y=-5  
E2:  x=2y-1
Substitute x=2y-1 into E1 and solve for y.
2y-1+2y=-5
4y-1=-5
4y-1+1=-5+1
4y=-4
4y/4=-4/4
y=-1
Now substitute y=-1 into E2 and solve for x.
x=2(-1)-1
x=-2-1
x=-3
The solution is (-3,-1) 
Happy Calculating!!!