Hi Brainiac
-2x+y=1
-4x+y=-1
We need to solve -2x+y=1 for y
Now let's start by adding 2x to both sides
-2x+y+2x=1+2xy=2x+1
Substitute 2x+1 for y in -4x+y=-1
-4x+y=-1
-4x+2x+1=-1
-2x+1=-1
Add -1 to both sides
-2x+1-1=-1-1
-2x=-2
Now divide both sides by -2 so we can fine the value for x
-2x/-2= -2/-2
x=1
The last step is to substitute 1 for x in y=2x+1
y=2x+1
y=(2)(1)+1
y= 2+1
y= 3
Answer : D , (1,3)
Good night :)
