math question! please help!

Answer:
the correct choice is marked
Step-by-step explanation:
The red line has intercept -3 and slope 1/3, so is ...
y = 1/3x -3
The blue line has intercept +1 and slope -1, so is ...
y = -x +1
The graph solves this system of equations, which can also be written as the single equation ...
y = y
1/3x -3 = -x +1