X+y=-1
3x-y=21
add them equations
x+y=-1
<u>3x-y=21 +</u>
4x+0y=20
4x=20
divide by 4
x=5
x+y=-1
5+y=-1
minus 5 both sides
y=-6
(x,y)
(5,-6)
D is answer
        
             
        
        
        
Answer:
I would say parallelogram. So the rectangle still fits but more shapes can be applied.
 
        
             
        
        
        
Your answer is A 
It cannot be C because the line y > -2  uses the (>) greater than symbol. 
When equations have a greater than symbol, they are graphed using a <u>dotted line. </u>
It cannot be D because the line is  y ≤ - l x-1 l 
with the less than or equal to sign (≤) , you use a <u>solid line</u> to graph 
With the<u> greater than</u> symbol for y > -2 , the shaded region must be <em>above </em>this line. 
With the <em>less than </em>or equal to sign in y ≤ - l x-1 l , the shaded region must be <em>below </em>the line. 
Hope I helped - message me if you have any questions :) 
 
        
             
        
        
        
Answer:
idk, sorry about that one