Which system of equations is represented by the graph?
A) y= x2 − 6x − 7
x − y = 1
B) y = x2 − 6x + 7
x + y = −1
C) y = x2 + 6x − 7
x − y = 1
D) y = x2 + 6x + 7
x + y = 1
