Answer:
<em>x+y=4</em>
Step-by-step explanation:
hello :
note : by identity you have x²-y² = (x-y)(x+y)
in this exercice : 2x²-2y² = 2(x²-y²) = 2 (x-y)(x+y)
means : 2 (x-y)(x+y) = 40
but x-y = 5
so : 2(5)(x+y) =40
x+y=40/10
<em>x+y=4</em>
To make it easier to graph this equation, you can manipulate it to get it in slope-intercept form. You'd do that like so:
7x + y = -7
y = -7x - 7
Now I can graph a bit more easily as I can more readily make out the slope and the y-intercept...
Answer:

Answer B is correct
Step-by-step explanation:

